问题 多项选择题

充填绝热层是最简单的绝热结构,常用于( )。

A.表面不规则的管道、阀门的保温

B.非纤维材料的预制保温瓦、保温板等绝热材料的施工

C.管、柱状保温体的预制保温瓦和保温毡等绝热材料的施工

D.表面不规则的设备的保温

答案

参考答案:A,D

解析: 充填绝热层是指由散粒状绝热材料如矿渣棉、玻璃棉、超细玻璃棉以及珍珠岩散料等直接充填到为保温体制作的绝热模具中形成绝热层,这是最简单的绝热结构。模具可用砖砌,木板、铁板制作或铁丝网捆制。这种结构常用于表面不规则的管道、阀门、设备的保温。

阅读理解

Jungle(丛林) country is not friendly to man,but it is possible to survive there. You must have the right equipment and you must know a few important things about woodcraft(山林野外知识). Then your chances of staying alive are very good.

No one should go into the jungle without the right equipment. You need lightweight clothing, a good knife, and a compass. Fishhooks and a line,a rifle,matches in a waterproof container and a poncho(雨披) are necessary too. So is a mosquito net(蚊帐) to protect the head.

In the jungle you can get hopelessly lost within five minutes after leaving known landmark(地界碑). That is why you should always carry a compass. In open country during the day, you can tell which way to go by studying the sun. At night the stars are sure guides to direction. But in most places the jungle rooftop is so thick that it is impossible to see the sun or the stars. Again and again you must check your position by the compass.

Keep alert(警惕的). Watch the ground in front of you carefully. Stop and listen now and again. Avoid haste(匆忙), and rest often. In a place that is hot and humid(潮湿的), the person who sets a fast pace will soon become tired. A steady and even pace is wisest in the long run.

If you lose your way, don't panic. Try to decide how long it has been since you were sure of your position. Mark the spot where you are with blazes on a tree. Put them on four sides of the tree, so that you will be able to see them from any direction. Then you can begin retracing your steps(going back exactly the way you have come), knowing that you can always find the spot from which you started. Except in an emergency, never try to travel the jungle at night.

Whenever possible, it is wise to follow streams and rivers that are going in your general direction. This may cause you many extra miles of travel. But in the end it will save time and energy. Nothing is more exhausting (extremely tiring) than hacking(cutting) a way through unbroken jungle.

Surviving in the jungle is a science. The jungle people have become perfect in this science, and you can too. Learn as much as you can about what to expect in the jungle. Make sure you have the right equipment. Then no part of the jungle will seem completely or frightening. In fact, you will be able to “live off” it for a long time.

小题1:To keep alive in the jungle, you should make it clear that the right equipment is _________.

A.more important than a knowledge of woodcraft

B.less important than a knowledge of woodcraft

C.just as important as a knowledge of woodcraft

D.not as important as a knowledge of woodcraft小题2:If you lose your way in the jungle, which of the following can NOT be done?

A.Check your position by the compass again and again.

B.Decide how long ago it was that you got lost.

C.Tell which way to go by studying the sun/the stars.

D.Mark blazes on four sides of a tree and be sure to see them from any direction.小题3:The author is strongly against traveling at night probably because __________.

A.one tends to move too slowly at night

B.some animals will attack you

C.emergencies occur most frequently at night

D.it is more difficult to check your position小题4:“It is wise to follow streams and rivers”, which will ensure you to _________.

A.avoid animals’ attacks

B.save many extra miles of travel

C.avoid hacking a way through unbroken jungle

D.have a rich supply of drinking water

填空题