问题 选择题

以下化学药品保存或实验操作正确的是( )

A.保存浓盐酸

B.保存固体氢氧化钠

C.稀释浓硫酸

D.点燃酒精灯

答案

答案:A

题目分析:本题难度不大,A选项是正确的;B选项错在不能使用玻璃塞,因为强碱可以和玻璃成分二氧化硅反应,如果使用玻璃塞,会使玻璃塞紧粘试剂瓶,无法打开;C选项是浓硫酸的稀释,应该还缺少玻璃棒不断搅拌,浓硫酸也应该沿着烧杯内壁往下缓缓注入;D选项错误非常明显,酒精灯的操作不能使用一盏酒精灯去点燃另一盏酒精灯。故选择答案A。

点评:加强对化学实验的认识和积累。

阅读理解

Once there was a piano player in a bar(酒吧). People came just to hear him play. But one night, a lady asked him to sing a song.

‘I don’t sing,’ said the man.

But the lady told the waiter, ‘I’m tired of listening to the piano. I want the player to sing!’

The waiter shouted across the room, ‘Hey, friend! If you want to get your money, sing a song!’

So he did. He had never sung in public before. Now he was singing for the very first time! Nobody had ever heard the song Mona Lisa sung so beautifully!

He had talent(天赋) he was sitting on! He may have lived the rest of his life as a no-name piano player in a no-name bar. But once he found, by accident, that he could sing well, he went on working hard and became one of the best-known singers in the US. His name was Nat King Cole.

You, too, have skills and abilities. You may not feel that your talent is great, but it may be better than you think. With hard work, most skills can be improved. Besides, you may have no success at all if you just sit on your talent.

小题1:The lady asked the player to sing a song because ______________.

A.she had paid him for this

B.she knew him very well

C.she wanted to have a change

D.she enjoyed his singing小题2: Nat King Cole succeeded because ______________.

A.the lady helped him a lot

B.he caught the chance

C.he continued to play in the bar

D.he stopped playing the piano小题3:From the story we know if you have some talent, you should ______________.

A.hide it and wait

B.ask others for help

C.pay no attention to it

D.work hard to improve yourself

选择题