李冰同学用两根吸管和一杯水制作了一个简易嘴喷雾剂，试画出两根吸管摆放的位置。

关于土的塑性指数不正确的有( )。

A．塑性指数愈大，可塑性就愈强
B．塑性指数表示黏性土处在可塑状态的含水量变化范围
C．黏性土的天然含水量和塑限的差值与塑限之比称为塑性指数
D．液限和塑限的差值称为塑性指数

    The sandstorm has a bad effect on human beings, but it also brings some good results. There wouldn’t have been our Chinese nation if there had been no sandstorms. Sandstorms have existed for millions of years, while the written history of human beings has lasted only 5,000 years. The Loess Plateau(黄土高原) was formed by sandstorms over millions of years. The Yellow River, while moving through the Loess Plateau, carries a great deal of sand and has formed the North China Plain. The Loess Plateau is regarded as the place where Chinese civilization(文明) began. If there had been no Loess Plateau, the North China Plain wouldn’t have existed, nor would have the Chinese civilization.

Sandstorms don’t bring only loess to human beings. When sandstorms move from central Asia to the Pacific regions, they carry some minerals into the air, which will later fall into the ocean in the form of rain. The minerals will help some planktons(浮游生物) to survive. The planktons are eaten by small shellfish, and fish live on these small shellfish, and fish are eaten by humans. This forms a biological chain which shows a relation between humans and nature.

So it is unrealistic to say we should stop sandstorms. What we can possibly do is to reduce their bad influence as much as we can.

59. The underlined sentence in the first paragraph probably means _________.

A. there are many sandstorms in China

B. the land of China was made by sandstorms

C. sandstorms helped to form Chinese civilization

D. the history of sandstorms was longer than that of Chinese nation

60. How does the sandstorm help to form the biological chain?

A. The sandstorm carries lots of rain into the ocean.

B. The sandstorm helps some minerals fall into the ocean.

C. Some minerals directly fall into the ocean in the form of rain.

D. The sandstorm moves from central Asia to the Pacific regions.

61. The writer thinks that _______.

A. the sandstorm only has a bad effect on human beings

B. sandstorms bring about lots of trouble, but we can still make use of them

C. without sandstorms, there would be no Chinese civilization and human beings

D. sandstorms play an active role in the Chinese civilization, so we should protect them

62. The text mainly talks about _______.

A. the history of sandstorms        B. what the biological chain is

C. how the Loess Plateau formed    D. the good effects of sandstorms

直埋线路在市区人行道埋深为（）米。

白箱测试方法重视 【5】 的度量。

输入乘车日期有三种方法，包括：选择输入法、直接输入法、（）。

A.数字键输入法

B.字母键输入法

C.快捷键法

D.菜单法