汽车发动机产生震动，并发出尖锐的金属敲击声可能和汽油的（）有

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问题多项选择题

汽车发动机产生震动，并发出尖锐的金属敲击声可能和汽油的（）有关系。

A、研究法辛烷值

B、抗爆指数

C、实际胶质

D、硫含量

答案

参考答案：A, B

完形填空

第二节完形填空（共20小题；每小题1.5分，满分30分）

阅读下面短文，从短文后各题所给的四个选项（A、B、C和D）中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。

Several months ago, my 22－year－old niece phoned me. “Aunt,” she said in her sweet voice, “the blood bank called and asked if I would donate blood. Would you come and donate with me?” I couldn't 21 her though I had never done that before.

I didn't know before going to the blood bank 22 I would be able to donate blood in the 23 of someone specific. There was a bulletin board with photos of children who were

24 at the Children's Hospital where I lost my daughter to 25 two years ago, so my heart went out to these children who were 26 cancer. One photo was of a little black girl, only nine. I 27 to donate my blood in Alexis's name. A month later, I 28 , and then a month after that, I went back again. I felt this was something I could do, 29 I made a promise to myself to go as often as possible.

One morning I heard a newscaster（播音员） 30 about a young girl named Alexis on TV. 31 , that's my Alexis from the blood bank who had lost her battle with cancer! My heart 32 . As I sat with tears running down my face, I listened to Alexis's story she left behind. I wasn't 33 to hear what an extraordinary child Alexis was, 34 I saw it in her eyes when I saw her 35 at the blood bank. She had the most angelic（天使般的）face, and a smile 36 of joy and courage. I never met this wonderful child, but she surely 37 me.

I am always telling myself that even though I do something that doesn't take 38 of my time, effort or money, it doesn't mean that what I do has no 39 . Every little thing we do to 40 another has value to the one who needs it.