阅读理解。 Scientist Without Laboratories When you hear the word 'scitentist', what do you think of? Many people think scientist are people in clean white coats who work in labs. And some scientists do work in labs. But there are 1 scientist who work in woods and jungles. These scientists are called 'animal behavior (行为) scientists', and they study animals as they live in nature. Why don't these scientists catch animals and study them in zoos? The 2 is in the word'behavior'. Animals behavior scientists want to learn 3 animal behave in their wild homes. When animals live in cages (笼子) or in zoos, they do not act the same as they do when they are 4 . They may fight 5 each other, or they may not eat, or they may not raise (抚养) their babies as they usually would. To see real animal behavior, scitentists must go where the animals 6 . So animal behavior scientists go into the jungles, the woods or the desert. There, their most important 7 are their eyes and ears. They watch and listen to the animals very 8 . They write down everything that happened in notebook. 9 they live near the animals, the scientists are careful not to frighten them. If the scientists are luncky, the animals will 10 no attention to them. Then the scientists can see how the animals really live. The behavior scientists hope what they've learned about animal behavoir can provide clues (提供线索) to help people learn to live together more happily. (     )1. A. another (     )2. A. answer (     )3. A. when (     )4. A. happy (     )5. A. of (     )6. A. live (     )7. A. machines (     )8. A. truly (     )9. A. But (     )10. A. pay B. other B. question B. where B. free B. among B. run B. tools B. carefully B. Unless B. spend C. others C. problem C. how C. sad C. for C. play C. thoughts C. woderfully C. Though C. take D. the other D. text D. why D. angry D. with D. eat D. ways D. nicely D. As if D. cost