A、Typically one. B、Usually two. C、At least three. D、More than four. A

Most people do not have a high opinion of bats. Bats often appear in movies and literature as terrifying creatures to be avoided. The animals have even been linked in popular culture to vampires, seeking to attack and drink the blood of human victims. In reality, bats are usually not a threat to people. Like other wild animals, some bats can carry the dangerous virus rabies. But bats can do good things for people and the environment. For example, bats eat a lot of different insects that can harm our environment. But a serious disease is currently threatening the bat population in many parts of the United States. The disease is a fungus called white-nose syndrome. It has killed more than 6 million bats across North America since 2007. Bats catch the fungus through their skin while resting on the walls of mountain caves. Biologist Lindsay Rohrbaugh says the disease spreads quickly and can lead to strange behaviour in bats. “Bats are arousing more often than they are supposed to be during hibernation. And when they do that, they are unable to find food, and they unfortunately die.”
In Washington D.C., researchers are studying how white-nose syndrome is affecting the area’s nine species of bats. Some scientists are trapping bats on an island in the middle of the Anacostia River to test for the disease. The group is receiving federal money to help carry out their studies. Marco Carvello is with the D.C. government’s Department of Energy and Environment. He says scientists are concerned that the disease is continuing to greatly reduce the bat population. “They typically have one child a year when they reproduce. So, that’s another reason that white-nose has been so detrimental. They don’t have a lot of babies.” The bat deaths are affecting the quality of human life in many ways, according to Lindsay Rohrbaugh. “Without bats, we are seeing an increase of mosquitoes and other pests that are destroying food sources for us. And I think that’s only going to get worse over time if we don’t find some way to protect the species that we have left.”
One theory is that some bats are no longer returning to caves to avoid getting sick. This means more of them are now making their way into cities, where contact with humans is more likely. Experts advise people to keep away from bats in case they are infected with rabies. Instead, they say animal control officers should be called to come and safely remove the animals.
Questions 19 to 22 are based on the recording you have just heard.
19. Why do most people have a dislike of bats?
20. Where do the scientists studying bats get their research funds?
21. How many children does a female bat produce in a year?
22. Why do experts advise city dwellers to keep away from bats?