问题 单项选择题

GN-C型制氮机操作准备工作包括()

1、检查各部外接气管、冷却水管和电源是否接好。

2、检查已接好的各气、水管路接头是否有松脱,并用扳手扳紧。

3、检查电器线路各接头接触是否良好,有否松动、脱开,并用扳手或螺丝刀上紧。

4、插上程序控制器、控氧仪或氮气分析仪的电源插头及各控制电磁换向阀和程序控制器的联接插件。

5、打开空压机、冷却器的冷却水阀门,直至水畅通,流量计示数正常应520Kg/Cm2左右。

6、用手转动空压机皮带轮数圈,螺杆压缩机不用转动皮带轮,然后按下电源开关,启动空压机空运转10分钟,正常后升压运转。

7、系统查漏。

A、①②④⑤⑥⑦

B、①②③⑤⑥⑦

C、①②③④⑥⑦

D、①②③④⑤⑥⑦

答案

参考答案:D

阅读理解

阅读理解。

     Modern life is impossible without traveling. The fastest way of traveling is by plane. With a modern airline

you can travel in one day to places which it took a month or more to get to a hundred years ago.

     Traveling by train is slower than plane, but it has its advantages (优势). You can see the country you are

traveling through. Modern trains have comfortable seats and dining-cars. They make even the longest journey

enjoyable.

     Some people prefer to travel by sea when possible. There are large liners and river boats. You can visit

many other countries and different places. And traveling by sea is a very pleasant way to spend a holiday.

     Many people like to travel by car. You can make your own timetable. You can travel tree or four hundred

miles or only fifty or one hundred miles a day, just as you like. You can stop wherever you wish-where there

is something to see, at a good restaurant where you can enjoy a good meal, or at a hotel to spend the night.

That is why traveling by car is popular for pleasant trips, while people usually take a train or plane when they

are traveling on business.

1. If you want to go to a faraway place in the shortest time, you'd better travel ______.

A. by train

B. by sea

C. by plane

D. by car

2. If you want to travel more freely, the best way is ______.

 A. by train

B. by sea

C. by plane

D. by car

3. The passage tells us that all the ways of traveling are enjoyable except traveling _______.

A. by train

B. by sea

C. by plane

D. by car

4. The reason why businessmen usually take a train or plane is probably to _______.

A. save time

B. enjoy themselves

C. visit more places

D. travel farther

5. From the passage we can see that _______.

A. all the ways of traveling today are much faster than those a hundred years ago

B. Each way of traveling that is mentioned has its own advantage

C. different people like different ways of traveling

D. more and more new ways of traveling will be invented

多项选择题