问题 填空题

一个氧分子是由两个氧原子组成的,氧原子半径约为0.074纳米,1纳米=10-9米,用科学记数法表示氧原子的半径约为:______米.

答案

0.074×10-9米=7.4×10-11米.

答:用科学记数法表示氧原子的半径约为7.4×10-11米.

阅读理解

阅读理解。

How do I like to travel?

     Many people like to travel by plane, but I don't like it because an airport is usually far from the city.

You have to get there early and wait for hours for the plane to take off and it is often late. You can't open

the window. You can't choose the food. Planes are fast, but they still take hours to get out of the airport

and into the city.

     I like traveling by train. I think trains are safe. Railway stations are usually in cities. When you are late

for a train you can catch another one .You can walk around in the train and open the windows. You can

see many interesting things on your way. I know it takes a little more time.

     I also like cars. You can start your journey when you want to, and you don't need to get to a railway

station or a bus stop. Also you can carry many things with you in a car. But sometimes there are too

many cars on the road.

1. Why do many people like to travel by plane?

A. Because it is fast.

B. Because it is safe.

C. Because you can walk around in the plane.

D. Because it's cheap.

2. Which is not the good thing about the train?

A. It is safe.

B. It takes a little more time.

C. You can open the windows.

D. It's not comfortable (舒适的).

3. If you want to take a lot of things with you ,what do you take to go out?

A. A bus        

B. A bike      

C. A train    

D. A car

4. What is the bad thing about the car ?

A. You needn't go to a station

B. You can start your journey when you want to.

C. There are too many cars on the road.

D. It's not safe

5. What does the writer think of the plane ,train and car?

A. He thinks it takes a lot of time to go to and get out of the airport.

B. He likes to take a train because it takes a little more time.

C. He likes to take a car because he has a car.

D. Both A and C.

名词解释