制作泡菜时，泡菜坛既要加盖，还要用一圈水来封口，这样做的目的是（ ） A．隔绝空

阅读理解。

     Edmund Halley was an English scientist who lived over 200years ago. He studied the observations of

comets which other scientists had made. The orbit of one particular comet was a very difficult mathematical problem. He could not figure it out. Neither could other scientists who dealt with such problems.

     However, Halley had a friend named Isaac Newton. Who was a brilliant mathematician. Newton

thought he had already which he had done it. He told Halley that the orbit of a comet had the shape of an

ellipse.    

     Now Halley set to work. He figured out the orbits of some of the comets that had been observed by

scientist. He made a surprising discovery. The comets that had appeared in the years 1531, 1607 and

1682 all had the same orbit. Yet their appearances had been 75 to 76 years apart.

     This seemed very strange to Halley. Three different comets followed the same orbit. The more Halley

thought about it, the more he thought that there had not been three different comets, as people thought. He decided that they had simply seen the same comet three times. The comet had gone away and had come

back again. It was an astonishing idea! Halley felt certain enough to make a prediction of what would

happen in the future. He decided that this comet would appear in the year 1758. There were 53 years to

go before Halley's prediction could be tested. In 1758 the comet appeared in the sky. Halley did not see

it, for he had died some years before. Ever since then that comet been called Halley's comet, in his honor.

1. Halley made his discovery _____.

A. by doing experiments             

B. by means of his own careful observation

C. by using the work of other scientists

D. by chance

2. Halley made a surprising but correct prediction in the year _____.

A.1704  

B.1705  

C. 1706    

D.1707

3. This text in general is about _____.

A. Halley and other scientists   

B. the orbit of a comet

C. Newton and Halley  

D. Halley and Halley

4. Which of the following is TRUE?

A. Edmund Halley was an American scientist

B. Halley made his discovery by doing experiments.

C. Isaac Newton was a famous mathematician.

D. The orbit of a comet had the shape of an around.

射干麻黄汤主要用于（）

A.寒饮郁肺的咳嗽上气证

B.外有寒邪，内有水饮之咳喘

C.水饮在里，正气不足的上气

D.痰浊上壅，肺气不利的咳喘

既善于治疗吐衄便血，又善于治疗肝火上炎之头痛目赤的药物是（）。

A.侧柏叶

B.地榆

C.大蓟

D.槐花

E.小蓟

什么是污水？简述其分类及性质。

重整油和HSCN作为制苯装置的原料在芳烃组成的比较上，它们的特点是（）。

A、重整油是二甲苯含量高，HSCN的苯含量丰富

B、重整油是苯含量丰富，HSCN的甲苯和二甲苯含量高

C、重整油的芳烃含量高，HSCN的非芳含量较高

D、两者区别不大