题干

黄河是我们的母亲河,化学学习小组的同学经过调查和搜集资料得知,可以通过①化学沉降(用明矾)②杀菌消毒(用漂白粉)③自然沉降 ④过滤等几个步骤对黄河水进行净化。请选择合理的操作顺序(   )

A:①③②④

B:①③④②

C:③④①②

D:③①④②

上一题 下一题 0.0难度 选择题 更新时间:2018-04-06 09:48:59

答案(点此获取答案解析)

D

同类题2

阅读下面短文,掌握其大意,然后从每题所给的四个选项中选出最佳选项。


    Asha looked out of the window on the plane. What a  1 ! The buildings were so tall. The city was large, much larger than her small town.

    Asha was on vacation in New York City. She was very   2  as she had always wanted to come since she was young. She read stories about it and studied its   3 . She knew how the island of Manhattan was bought from native Americans 300 years ago. She   4  knew people from all over the world came to live here. These people, like Asha,   5 a new life in New York.

    But Asha was only staying for fourteen   6 . She thought of these two weeks as a time to  7  herself to move back to New York. She would return to her small  8  , stay for one year, and then come to live in New York forever. So she had to plan this vacation   9.

    In New York Asha wanted to do10things. First, she wanted to look for a job. Next, she would find a place to live. She knew it was expensive to live in New York and that finding a good place to live was  11. And the third thing she wanted to do was to   12  her English. She had studied English for 12 years but didn't know  13   she could understand “real” English.

    Before leaving, her friends told her that New York was a14place. But Asha wasn't worried. She had studied New York carefully. She believed she would be safe.

      15   Asha saw the Statue of Liberty! The plane flew around it, and then began to slow down. Soon Asha was on the ground, getting ready to leave the plane — to greet her future.