Đề Ôn Thi Tốt Nghiệp THPT Tiếng Anh 2022 - Đề 5

Wuhan Coronavirus Looks Increasingly Like a Pandemic, Experts Say

Rapidly rising caseloads alarm researchers, who fear the virus may make its way across the globe. (34) __________, scientists cannot yet predict how many deaths may result. The Wuhan coronavirus spreading from China is now likely to become a pandemic (35) __________ circles the globe, according to many of the world's leading infectious disease experts. The prospect is daunting. A pandemic - an ongoing epidemic on two or more continents- may well have global consequences, despite the extraordinary travel restrictions and quarantines now imposed by China and (36) __________ countries, including the United States.

Scientists do not yet know how (37) __________ the new coronavirus is, however, so there is uncertainty about how much damage a pandemic might cause. But there is growing consensus that the pathogen is readily transmitted between humans. Many scientists have found that the Wuhan coronavirus is spreading more like influenza, which is highly (38) __________ than its slow-moving viral cousins, SARS and MERS. "It's very, very transmissible, and it almost certainly is going to be a pandemic," said Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Disease.

(Adapted from https://www.nytimes.com/2020/02/02/health/coronavirus-pandemic-china.html)

Martin Luther King, Jf, is well- known for his work in civil rights and for his many famous speeches, among which is his moving "I have a dream" speech. But fewer people know much about King's childhooD. M.L., as he was called, was bom in 1929 in Atlanta, Georgia, at the home of his maternal grandfather. M.L.'s grandfather purchased their home on Auburn Avenue in 1909, twenty years before M.L was bom. His grandfather allowed the house to be used as a meeting place for a number of organizations dedicated to the education and social advancement of blacks. M.L. grew up in the atmosphere, with his home being used as a community gathering place, and was no doubt influenced by it.

M.L.'s childhood was not especially eventfully. His father was a minister and his mother was a musician. He was the second of three children, and he attended all black schools in a black neighborhood. The neighborhood was not poor, however. Auburn Avenue was an area of banks, insurance companies, builders, jewelers, tailors, doctors, lawyers, and other businesses and services. Even in the face of Atlanta's segregation, the district thrived. Dr. King never forgot the community spirit he had known as a child, nor did he forget the racial prejudice that was a huge barrier keeping black Atlantans from mingling with whites.

Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a radioactive substance such as carbon-14 has a known half-life, the amount of carbon-14 remaining in an object can be used to date that object.
Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon-14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old.
Carbon dating cannot be used effectively in dating objects that are older than 80,000 years. When objects are that old, much of the carbon-14 has already decayed into nitrogen-14, and the miniscule amount that is left doesn't provide a reliable measurement of age. In the case of older objects, other age- dating methods are available, methods which use radioactive atoms with longer half-lives than carbon has.