1. Her expression____(导致)me to believe there was some problem.
2. The____(想法)of going out in the rain and fog discouraged him.
3. She is an English teacher and she has a good          (知识)of English.
4. The waitress s ____ me coffee after the meal.
5. Hunan tigers are one of             (濒临灭绝的)animals.
6. At first, they felt a bit t ___   , then they became more and more confident.