简述计算机机箱的作用。

男性，45岁。梨形心，心尖区可闻及舒张期隆隆样杂音，局限不传导。该杂音的形态是（）。

A.一贯型

B.递增型

C.递减型

D.递增递减型

E.连续型

空气的密度随高度的增加而______，所以气球在上升过程中受到的浮力会逐渐______．

We like to consider ourselves the superior race, and we are. It’s true that we are getting to know more and more, and we actually live in “the information age”. Our human vanity(虚荣心) makes us believe that we really have to know everything! Surprisingly, we do not have this ability. The question “what is happening in the Bermuda Triangle” is the very proof.

Where is the Bermuda Triangle located? The mysterious triangle is believed to be situated between Florida, Bermuda and Puerto Rico, where too many unusual events have happened.

On December the 5^th 1945, five U.S. military planes took off from Florida on a clear day only to disappear over Bermuda. Furthermore, some other disappearances took place; in 1947, an American C54 plane simply disappeared at 100 miles from Bermuda; at 80 miles, a Star Tiger plane disappeared in 1948.

Even Columbus had trouble in Bermuda. Some of his journals were about the strange happenings there: “the waters are changing their colors” and “compasses are going wild”.

Maybe it’s why it is called the Devil’s triangle or the Atlantic cemetery.

Many hypotheses were stated in order to explain the strange events. In spite of these attempts, the mystery of the Bermuda Triangle remains unsolved.

Some people get to say that maybe aliens are involved in it. Other imaginative scientists relate the happenings in Bermuda to Einstein’s theory, saying that the missing ships and planes are translated to another dimension of space and time and taken into another world.

Maybe we will just have to wait to go to Heaven and ask the One who made it. The answer will surely be a satisfying one!

小题1:The writer may probably think that______.

A．humans have to and can know everything strange

B．the missing ships are taken into another world

C．humans can know more in “the information age”

D．God created the mystery of the Bermuda Triangle小题2: Columbus’ journals told us that in Bermuda _______.

A．an American C54 plane disappeared

B．there were some strange happenings

C．the compasses were lost

D．a cemetery was found小题3:The underlined word “hypotheses” in the 6^th paragraph probably means______.

A．guesses

B．reports

C．places

D．stories小题4:The purpose of the writer is to______.

A．tell some stories about the Bermuda Triangle

B．warn people not to travel to the Bermuda Triangle

C．laugh at man’s vanity to know everything

D．prove man does not have the ability to know all

冷形变金属在回复阶段可消除______。

A．微观内应力

B．宏观内应力

C．宏观内应力和微观内应力

在货物运输业增值税专用发票税控系统，“发票核准信息变更”选项中可进行变更的项目有？（）

A.批准使用的发票种类

B.购票方式

C.购票数量

D.退票限定天数