为了了解本班同学所穿鞋子的尺码，可对全班同学采用哪种调查方式______．

阅读理解。

     There have been many great inventions  that changed the way we live.  The first great invention was

one that is still very important today - the wheel. This invention made it easier to carry heavy things and

to travel long distances.

     In the early 1800s the world started to change.  There was little unknown land in the world. People

began to work to make life better.

     In the 19th century, many great inventions were made. Among them were the cameras and the light

bulbs. There were more great inventions  in the early  20th  century,   such as  the  helicopters in 1907,

movies with sound in 1910 and jet planes in the 1930s. This was also a time when a new material was

first made. Nylon came out in 1935. It changed the kind of clothes people wear.

     By this time most people have had a very good life. Man has a desire to explore more.  The world

was known to man but the stars were not. Man began looking for ways to go into space. Russia made

the first step. Since then other countries, including the United States and China,  have made their steps

into space.

     In 1969 man took his biggest step. An American first walked on the moon.  This  is certainly just a

beginning. New inventions will some day allow us to do things we have never dreamed of.

1. This passage mainly talks about ________.

A. why cars were very important

B. when the light bulb was invented

C. which country made the first step into space

D. the process (进程) of inventions

2. Nylon came out nearly at the same time as _______. 

A. the helicopter    

B. the camera  

C. jet planes  

D. movies

3. _______ made the first step into space.

A. Russia          

B. China      

C. America    

D. Japan

4. What does " a desire" mean in Paragraph 4?

A. a good way  

B. a new invention  

C. a strong wish  

D. a wonderful idea

5. Which of the followings is NOT true?

A. The wheel was the first great invention, but it is not very important today.

B. An American first stepped on the moon.

C. In the early 1800s there was little unknown land.

D. New inventions will change our lives greatly in the future.

作为污水生物处理技术，稳定塘的优点有( )。

A．能够充分利用地形，建设投资省

B．不受季节、温度等环境条件的影响

C．运行管理简单

D．占地面积小

如图甲所示，劲度系数为k的轻弹簧竖直放置，下端固定在水平地面上，一质量为m的小球，从离弹簧上端高h处自由下落，接触弹簧后继续向下运动．若以小球开始下落的位置为原点，沿竖直向下建立一坐标轴ox，小球的速度v随时间t变化的图象如图乙所示．其中OA段为直线，AB段是与OA相切于A点的曲线，BC是平滑的曲线，则关于A、B、C三点对应的x坐标及加速度大小，下列说法正确的是（　　）

A．x_A=h，a_A=0

B．x_A=h，a_A=g

C．xb=h+

D．xc=h+

在电力系统中正常运行中，电网电压的变化主要是由于系统中的无功负荷不平衡引起的，这时应调节发电机的（）。

A.转速

B.励磁

194号令-《民用航空安全信息管理规定》所称事故不包括（）。

A.由于自然原因造成的人员伤亡

B.航空器报废

C.人员死亡

D.航空器失踪