题干

以下物质保存方法不正确的是(  )

A:少量金属钠保存在煤油中

B:少量白磷保存在水中

C:浓硝酸保存在棕色试剂瓶中

D:氢氧化钠溶液保存在配有玻璃塞的细口瓶中

上一题 下一题 0.0难度 选择题 更新时间:2017-02-24 06:04:26

答案(点此获取答案解析)

D

同类题2

baby   car   enough    leave     anything    us
poor   rich   remember   surprised   took        whenever

    One a snowy evening, a rich lady was standing by the road. She was very worried. Her____ had broken down. Just then a poor man named Robert came. He was on his way back home from work as usual.
    The lady thought, “Is the man going to help me? He looks very cold and hungry. ”But to her ____ , he stopped and said with a smile, “What’s wrong, madam?” The lady told him what was happening.
    After forty minutes, the car was at last fixed by Robert. The lady wanted to pay him.
  “No, that’s ____  , madam.” he said, “I was just helping someone in need. If you really want to pay me back, I hope you ____ see someone in trouble, please give him a hand.” A few minutes later, the lady saw a shabby house by the road. She  ____  Robert's words, so she stopped. The hostess warmly asked her in. The lady could see that was a ____  family and they needed help. When the hostess was making tea in the kitchen, the lady ____ 500 dollars on the table and went away quietly. Robert came home later than before, thinking how hard their life was. Their ____  was to be born the next month but there wasn't ____  money. His wife went up to him, gave him a kiss and said softly, “Don't worry, dear! Everything’s going to be all right. A stranger has helped us out. ”
Let's always be ready to help others because helping others is helping ____  .