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.

电解水时，常在水中加入硫酸使反应容易进行，硫酸本身并不被分解．现用45g溶质质量分数为8%的硫酸溶液进行电解水的实验，一段时间后，产生1g氢气．计算：

（1）被电解的水的质量．

（2）电解后的硫酸溶液的溶质质量分数．