空压机一般采用多级压缩，船用空压机一般多为两级压缩。

权利的行使受到法律的保护，任何妨碍他人正当行使权利的行为都被（）。

A few years ago it was popular to speak of a generation gap, a disagreement between young people and their elders. Parents said that children did not show them proper respect and obedience, while children complained that their parents did not understand them at all. What had gone wrong Why had the generation gap suddenly appeared Actually the generation gap has been around for a long time. Many people argue that a gap is built into the fabric of our society.
One important cause of the generation gap is the chance that young people have to choose their own ways of life. In more traditional societies, when children grow up, they are expected to live in the same area as their parents, to marry people that their parents know and agree to, and to continue the family occupation. In our society, young people often travel great distances for their education, move out of the family home at an early age, marry or live with people whom their parents have never met, and choose occupations different from those of their parents.
In our easily changing society, parents often expect their children to do better than they did: to find better jobs, to make more money, and to do all the things that they were unable to do. Often, however, the p desire that parents have for their children are another cause of the disagreement between them. Often, they discover that they have very little in common with each other.
Finally, the speed at which changes take place in our society is another cause of the gap between the generations, In a traditional culture, elderly people revalued for their wisdom, but in our society the knowledge of a lifetime may become out of date overnight. The young and the old seem to live in two very different worlds, separated by different skills and abilities.
No doubt, the generation gap will continue to be a feature of American life for some time to come. Its causes are rooted in the freedom and changes in our society, and in the rapid speed at which society changes.

The main idea of the first paragraph is that ______.

A．the generation gap suddenly appeared
B．the generation gap is a feature of modem social life
C．people can reduce the generation gap
D．many critics argue over the nature of the generation gap

一个硬盘有10张盘片，盘片上每条磁道有60个扇区，每个扇区的字节数为512，柱面数为1000，第一张盘片的上面及最末一张盘片的底面作保护面，不存储信息，则该硬盘的总容量是()。

A．468.75MB

B．527.34MB

C．585.93MB

D．644.53MB

讲文明树新风——中国梦系列公益广告已成为社区文化一道亮丽的风景线，这些随处可见的广告悄然给社区居民的言行带来了可喜的变化。“随处可见的广告悄然给社区居民的言行带来了可喜的变化”表明（）

A.文化能够在改造世界的过程中转化为物质力量

B.文化对人的影响是无形的、被动的

C.文化对人的影响来自于特定的文化环境

D.文化对人的影响是深远的、持久的

机关管理程序的局部性调整是（）

A.创新性建立

B.结构性调整

C.整体性重构

D.功能性优化