根据句意，在答题卡标有题号的横线上，写出括号内所给单词的适当形式。

1. Lily and Rose are good friends and always keep their secrets to _____. (they)

2. We think more public activities will help change his _____ (active) life.  

3. The man kept remembering English words every day until he was in his _____. (forty)

4. How amazing it is! I _____ can't believe what she told me yesterday. (simple)

5. It's said that the police have put up those _____ (thief) drawings on the Internet.

下列关于汽包水位保护说法正确的是（）。

A、汽包水位保护应在锅炉点火前投入；

B、汽包水位保护应在点火后投入；

C、电接点水位保护为后备保护；

D、平衡容器水位保护为三取二。