Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the option that best fits each of the numbered blanks from 18 to 22.
Preserving the Night Sky: The Fight Against Light Pollution
At a time when interest in astronomy is on the increase, amateur astronomers (18) __________. The reason for this is that the night sky is gradually being lost due to light pollution, (19) __________. In response to this growing threat, the International Dark Sky Association has decided to award Dark Sky Reserve status to places that have so far escaped the adverse effects of light pollution. (20) __________. Up to now, only a handful of places have been granted Dark Sky Reserve Status, but there are plans for others to be added so that amateur astronomers can continue to enjoy the night sky just as much as their professional counterparts. (21) __________. Additionally, educational programs are also being developed to raise awareness among communities about the importance of reducing light pollution. If consistently supported by the governments and citizens, (22) __________.