下列不属于农业银行个人优质客户关系管理系统功能的是（）。A．市场细分 B．营销支持

低血容量休克液体治疗时一般不选用（）

A.白蛋白液

B.生理盐溶液

C.乳酸林格液

D.羟乙基淀粉

E.低分子右旋糖苷

“用DIS研究加速度与力的关系”实验中，应选用摩擦力      的（填“大”或“小”）轨道，选用的钩码的质量应      些（填“大”或“小”）．若某同学根据实验数据作出的加速度a与作用力F图线如右图所示，试分析图线不过原点的主要原因是                             ．

Despite the fact that comets are probably the most numerous astronomical bodies in the solar system aside from small meteor fragments and the asteroids, they are largely a mystery. Scientists do not know exactly what comets are or where they come from. Educated guesses are the best we have in hand.

Considering the role of comets in legend and the memory of man, it is remarkable that we still know so little, relatively, about them. The most famous comet of all, Halley’s Comet ( named for the man who predicted its return), was first sighted by the Chinese in 240 B．C．, and it has returned to terrify the people of the world on a regular basis every since then. The ancient considered it an object of ill omen. By mysterious coincidence, the arrival of Halley’s Comet coincided with such events as the battle of Hastings in 1066, the Jewish revolt of 66 A．D．, and the last battle of Attila the Hun against the Romans. Nor is it the only comet to fill man with awe, but merely the most famous in a rich aristocracy of blood-freezers.

Comets are even more fascinating to amateur astronomers than to professionals, because this is one area where amateurs can make major discoveries. Comet Ikeya Seki, one of the brightest comets to appear in this century was discovered in 1965 by a pair of Japanese amateurs, Ikeya and Seki. The person who discovers a new comet gets his (or her) name put on it. And amateurs have a head start in the race to discover new comets; the shorter focal lengths on their smaller telescopes give them a positive advantage over the huge telescopes such as Mount Wilson which is built to scan for galaxies, not comparatively short distances.

Most scientists tend to agree with astronomer Fred T. Whipple that a comet is really a large mushy snowball of frozen ices and gases ( ammonia, methane, possibly carbon dioxide) with a few bits of solid particles stuck inside. But no one is sure how comets are created in the first place.

Scientist believe that comets don’t exhibit their characteristic tail while they lurk fat out in space away from the warmth of the sun but, rather, wander in the form of frozen lumps, like icebergs. This is the core of the comets. Only when the comet approaches the heat of the sun, does the ice begin to melt and stream away in the form of visible gases. The tails of the comets stream out behind for, literally, astronomical distances. Halley Comet had a tail of 94 million miles long when it visited here in 1910．The Great Comet of 1843 had a tail of 186 million miles long.

Halley’s comet is mentioned in Paragraph 2（）

A. to introduce some famous historical events

B. to explain some traditional beliefs about comets

C. to demonstrate the harm it has done to man

D. to show its significance to human history

系统体系结构是用来描述系统各部分的结构、接口以及它们用于通信的（）。

A.一种机制

B.形式

C.原理

D.结构

刚进入西藏的上海援藏干部，对高原缺氧环境所产生的生理反应是（）

①造血功能增强，红细胞数目增加

②呼吸频率加快

③细胞大多以无氧呼吸获得能量

④心率加快

A.①③

B.①②

C.②③

D.②④