会计凭证按照编制的程序和用途不同可分为原始凭证和记账凭证。( )

关于质点，下面说法正确的是：

A．体积很小的物体可看作质点

B．研究乒乓球旋转时，可以把乒乓球看作质点

C．物体抽象为质点后，物体自身的大小和质量都可以忽略不计

D．在某些情况下，月球可以看作质点，某些情况下，小汽车不能看作质点

足少阴肾经的循行线，下列正确的有（）。

A.出于然骨之下

B.贯脊属肾，络膀胱

C.循喉咙，夹舌本

D.从肺出，络心，注胸中

E.循外踝之后，别入跟中

患儿机体处于红细胞生成缺铁期

A.4岁小儿，如果血液检测结果分别如下：100；红细胞游离原卟啉：增高；血清铁蛋白：减低

B.4岁小儿，如果血液检测结果分别如下：114；红细胞游离原卟啉：增高；血清铁蛋白：减低

C.4岁小儿，如果血液检测结果分别如下：126；红细胞游离原卟啉：正常；血清铁蛋白：减低

D.4岁小儿，如果血液检测结果分别如下：117；红细胞游离原卟啉：减低；血清铁蛋白：增高

E.4岁小儿，如果血液检测结果分别如下：115；红细胞游离原卟啉：减低；血清铁蛋白：正常

阅读理解。

     Sandstorms hit northwestern China's Gansu Province and North China's Inner Mongolia Autonomous Region on the first day this year. According to Sun Landong, a meteorologist with the Lanzhou

Meteorology Observatory, visibility was less than 100 meters in Minqin, a Gansu county near Inner

Mongolia, because of sand. When visibility drops to less than 1 kilometer, it is called a sandstorm. The

sandstorm in Minqin blew up dust in neighboring towns, such as Baiyin, Wuwei, Jinchang and Lanzhou,

the capital city of Gansu Province. Dust-laden winds also swept into Beijing. Brought by northwesterly

blowing at more than 20 meters per second, dust first reached the capital's suburbs at 7 a. m., downtown

areas at 9 a. m. The winds, which died down during the night, brought the temperature down to as low as 8 0C below zero and many flights put off their planned time from the city's airport.

     It is quite rare for sandstorms, which are frequent between March and June, to happen in winter,

when the earth is frozen. The sandstorms in Gansu and Inner Mongolia do not necessarily mean there will

be more of them in the spring than last year, when they were serious, but Beijing is taking it very seriously. It is reported that Beijing will spend 6 billion yuan (US 725 million) in preventing sandstorms in the

capital and has already set up a special team to make sure what causes them.

1. What is the main idea of the passage?

A. Sandstorms took place in Gansu.

B. Sandstorms happened on the first day of the new year.

C. Sandstorms are very serious,compared to last year.

D. Experts are trying their best to determine the cause of the sandstorm formed this year

2. Suppose the dust was 300 kilometers away from Beijing,it would reach Beijing about,          hours

    later if it travels at a speed of 20 meters per second?

A. 4.2

B. 1.5

C. 2.0

D. 2.5

3. Why did sandstorms begin in the winter this year?

A. Because there was little snow this season.

B. Because a lot of trees have been cut down.

C. Because people took few measures to control them.

D. It is not mentioned in the passage.

4. Which of the following doesn't belong to the bad effect the sandstorms have done in Beijing?

A. The temperature fell.

B. Flights put off their time to take off.

C. The air is dirty.

D. People had three days off

5. The author wrote the passage to           .

A. tell us the environments are becoming worse and worse

B. explain what measures people have taken to control sandstorms

C. make people realize the need to protect the environment

D. call on us to do what we can to save the earth.

某计算机字长16位的机器码1111 1111 0000 0000，表示无符号的整数时对应的十进制表达式为 (5) ，表示一个带符号整数的反码时，该机器码表示的十进制表达式为 (6) 。该数的补码是 (7) 。

A．0111111100000000

B．1000000011111111

C．1111111100000001

D．1111111011111111