用适当的词填空。

1. There are about two _______________ (百) students playing on the playground.

2. The mother is _______________ (自豪的) of her son,

    because he is very successful in his work.

3. There are many kinds of English _______________ (字典) in this bookstore.

    You can choose the one you like.

4. Look at the photo _______________ (仔细地), and you will find our teacher.

5. Would you mind _______________ (打开) the window? We need some fresh air.

下列事实能证明在化学反应中分子可分的是[ ]

A．冷却硝酸钾的热饱和溶液有硝酸钾晶体析出

B．水蒸气液化成水

C．水通电可以得到氢气和氧气

D．蔗糖放入水中不见了