拉线分为垂直V形和水平V形两种。主要用在（）时，在拉力合力点上下两处各安装一条拉线，

阅读理解。

     Almost everyone in the world uses oil in some way. Cars, buses, planes and many trains and ships

also need oil. Even our bicycles need oil. Indeed the whole world would stop if there was no oil. Today

there is a growing need for oil in the world. So people are looking for it everywhere. They look for oil

in deserts, in the mountains and under the sea. Quite often they find nothing, but the search for oil always

goes on. What are the largest oil producers in the world? The U.S, the U.S.S.R., and countries of the

Middle East. But China is catching up fast. Before liberation we used to buy nearly all our oil from the U.S.

Many foreign people said China was "oil-poor". But since liberation oil has been found in many parts of the

country, today everyone agrees that China is rich in oil. Our oil will not only meet the great need in our

country, but also be sold to other countries.

1. We can _____ without any oil.

A. run a bus or a ship

B. run planes or trains

C. run no machines

D. ride a bike

2. "a growing need for oil" probably means _____.

A. oil is growing more and more

B. today people need more oil than before

C. people need less oil now

D. oil is needed to grow

3. Oil can be found _____.

A. under the ground

B. under the sea

C. under the deserts

D. A B and C

4. _____ was once said to be poor in oil.

A. U.S.

B. U.S.S.R

C. China

D. The middle East

5. People search for oil everywhere, _____.

A. and oil can be found easily

B. but oil is very difficult to find

C. but can find nothing

D. and oil is growing more and more

Ⅰ类民用建筑工程，室内环境污染物苯的浓度限量不得大于（）mg/m³。

A．0.08

B．0.09

C．0.12

D．0.2

马科维茨投资组合理论的假设条件不包括( )。

A．证券市场是有效的

B．存在一种无风险资产，投资者可以不受限制的借入和贷出

C．投资者都是风险规避的

D．投资者在期望收益率和风险的基础上选择投资组合

更换钢柱销式挠性联轴器的缓冲垫应拆下（）

A.电动机

B.水泵

C.联轴器

D.钢制柱销