In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

In the 1960s, the first human explorations of space began. Today scientists often debate the future of manned space flight. Should we aim for the moon again, or for Mars? It always comes down to concerns about the length and expense of such journeys. Mars is a much more difficult challenge than the moon.
Mars is so far away that is world take about two years for a human crew to complete the round trip, including time spent to the planet's surface. On the other hand, we know the moon can be visited in a fraction of that time, as was proven by the Apollo 11 mission in 1969. Distance poses other dilemmas. A popular movie, Apollo 13, tells the exciting story of how NASA managed to rescue the astronauts of the ill-fated Apollo 13 mission to the moon. With the tremendous distance between Earth and Mars, emergency retrievals like this would be impossible. The moon seems more feasible from this point of view.
As with most projects, the crux of the matter is economics. In fact, NASA has estimated that a manned flight to Mars would cost five hundred billion dollars! Critics argue that Mars is too far and the moon is too useless to us to justify any manned space flights at all. Nevertheless, should we choose to go ahead with space travel, it seems that returning to the moon is a much more likely proposition than Mars.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.
The Eighth Wonder of the World The Thames Barrier is a major part of the flood defense scheme for protecting London (35) ______ rising water levels. The defenses (36) ______ include raised river embankments and additional flood gates at strategic points, including the Barking Barrier. The unique structure that is the Barrier spans the 520- metre wide Woolwich reach and (37) ______ of 10 separate movable gates, each pivoting and supported between concrete structures which house the operating machinery. When raised, the four main gates (38) ______ stands as high as a five-storey building and as wide as the opening of Tower Bridge. Each (39) ______ 3700 tones. During the first twelve years of operation the Barrier has been closed twenty nine times to protect London.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.
The Eighth Wonder of the World The Thames Barrier is a major part of the flood defense scheme for protecting London (35) ______ rising water levels. The defenses (36) ______ include raised river embankments and additional flood gates at strategic points, including the Barking Barrier. The unique structure that is the Barrier spans the 520- metre wide Woolwich reach and (37) ______ of 10 separate movable gates, each pivoting and supported between concrete structures which house the operating machinery. When raised, the four main gates (38) ______ stands as high as a five-storey building and as wide as the opening of Tower Bridge. Each (39) ______ 3700 tones. During the first twelve years of operation the Barrier has been closed twenty nine times to protect London.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.
The Eighth Wonder of the World The Thames Barrier is a major part of the flood defense scheme for protecting London (35) ______ rising water levels. The defenses (36) ______ include raised river embankments and additional flood gates at strategic points, including the Barking Barrier. The unique structure that is the Barrier spans the 520- metre wide Woolwich reach and (37) ______ of 10 separate movable gates, each pivoting and supported between concrete structures which house the operating machinery. When raised, the four main gates (38) ______ stands as high as a five-storey building and as wide as the opening of Tower Bridge. Each (39) ______ 3700 tones. During the first twelve years of operation the Barrier has been closed twenty nine times to protect London.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.
The Eighth Wonder of the World The Thames Barrier is a major part of the flood defense scheme for protecting London (35) ______ rising water levels. The defenses (36) ______ include raised river embankments and additional flood gates at strategic points, including the Barking Barrier. The unique structure that is the Barrier spans the 520- metre wide Woolwich reach and (37) ______ of 10 separate movable gates, each pivoting and supported between concrete structures which house the operating machinery. When raised, the four main gates (38) ______ stands as high as a five-storey building and as wide as the opening of Tower Bridge. Each (39) ______ 3700 tones. During the first twelve years of operation the Barrier has been closed twenty nine times to protect London.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the best option for each of the blanks.
The Eighth Wonder of the World The Thames Barrier is a major part of the flood defense scheme for protecting London (35) ______ rising water levels. The defenses (36) ______ include raised river embankments and additional flood gates at strategic points, including the Barking Barrier. The unique structure that is the Barrier spans the 520- metre wide Woolwich reach and (37) ______ of 10 separate movable gates, each pivoting and supported between concrete structures which house the operating machinery. When raised, the four main gates (38) ______ stands as high as a five-storey building and as wide as the opening of Tower Bridge. Each (39) ______ 3700 tones. During the first twelve years of operation the Barrier has been closed twenty nine times to protect London.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
When ice skating, it is very important to have good equipment and use it properly. When choosing a pair of skates, look for high quality skating shoes with sharp steel blades. Choosing the right size stakes is also important. The leather shoes, which are called boots, should reach up to about the middle of your calf.
Make sure that your skate boots fit snugly. First, put on two pairs of cotton or lightweight wool socks. Then, step into your skates. Your heels should not be able to slide up and down in the boots. If your boots do not fit properly, they will not support your feet, and the skates won't respond correctly when you move your muscles. It will look like your ankles are weak and will cause you severe discomfort.
Each boot is attached a metal blade by crews at two different places. The blade of skate is a narrow piece of steel that is strong enough to support the weight of your body. The bottom of the blade, which touches the ice, is hollowed out, leaving two very thin edges. Stakes have guards, pieces of wood or rubber that fit over blades to protect these edges. You should use these guards when wearing your skates off the ice, and when you are not using your skates.