问题 单项选择题

为了防止筒形活塞式柴油机气缸套水冷壁穴蚀,在轮机管理中的措施有()。

Ⅰ.改用加厚气缸套

Ⅱ.减小活塞与缸套的间隙

Ⅲ.对冷却水进行处理

Ⅳ.减小气缸间距

Ⅴ.防止冷却水高温

Ⅵ.保持冷却水压较高而稳定

A.Ⅰ+Ⅱ+Ⅲ+Ⅴ

B.Ⅱ+Ⅲ+Ⅴ+Ⅵ

C.Ⅰ+Ⅲ+Ⅳ+Ⅴ

D.Ⅲ+Ⅳ+Ⅴ+Ⅵ

答案

参考答案:B

解析:

上述所有措施都可以作为防止筒形活塞式柴油机气缸套水冷壁穴蚀的措施,但其中I、Ⅳ两种措施只有在柴油机设计及制造过程中才能应用,而在轮机管理中由于船舶条件限制不能采用。

阅读理解

阅读理解。

     Jane always goes to school early. She likes to talk to her friends before class. After school she does not

go home early. She is always late. Jane stops to see the animals in the pet shop. She likes to see the dogs.

One of them is a little dog. She watches the little white dog play in the window of the shop. She watches for

a long time, so she comes home late.

     One day her father and mother ask why she is late, and she tells them about the little dog in the pet shop.

     Jane is not late the next day. She stops to look in the window of the shop. But she doesn't see the little

white dog, and she is very sad. She is also very happy, today is her birthday.

     Mother shows her a big birthday cake and Father gives her a birthday surprise. He gives the little white

dog from the shop. Jane is very happy. The next day Jane does not come home late. She runs home to play

with the white dog.

1. Before class begins, Jane usually ________.

A. plays with her friends

B. talks to her friends

C. looks at the dogs in the window

D. have a break

2. After school Jane ________.

A. comes home early

B. does not go home late

C. plays with the dogs

D. always goes home late

3. Jane likes ________ best.

A. the pet shop

B. the little white dog

C. little animals

D. the window of the shop

4. Who bought (买) the little white dog?

A. Jane.

B. Jane's friends.

C. Jane' s father.

D. Nobody.

5. The birthday surprise is ________.

A. a big cake

B. some presents

C. some flowers

D. the little white dog

简答题