根据句意和首字母写出相应的单词。

1. Our teacher always e_____ us to work hard at English and do more for people in the future.

2. S_____, when he went into the dark hole for the first time alone, he didn't come up any more.

3. If you go out in summer, you'd better wear sunglasses to p_____ your eyes from strong sunlight.

4. Giant pandas are in danger now, they are e_____ animals. 

5. Every year a lot of t_____ come to visit the Palace Museum to see those things used in the past.