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Air rushes toward the equator from the north and south ______ .
A．because of the dry air
B．because of the cool air
C．because of the lower air pressure
D．because of the higher air pressure
答案
更多“Air rushes toward the equator from the north and south ______ .A．because of the dry airB．b”相关的问题
第1题
We know that there is air all around the world. We could not breathe without air. Airplanes could not fly without air. Thy need air to lift their wings. Airplanes cannot fly very high because as they go higher the air gets thinner. If we go far enough away from the earth, we find there is no air. What is the sky？ The sky is space. In this space there is nothing except the sun, the moon and all the stars. Scientists have always wanted to know more about the other worlds in the space. They have looked at them through telescopes and in this way they have found out a great deal. The moon is about 384,000 kilometers away from the earth. An airplane cannot fly to the moon but there is a thing that can fly even when there is no air. This is rocket.
I am sure that you are asking, “How does a rocket fly？” if you want to know, get a balloon and then blow it up until it is quite big. Do not tie up the neck of the balloon. Let go! The balloon will fly off through the air very quickly. The air inside the balloon tries to get out. It rushes out through the neck of the balloon and this pushes the balloon through the air. It does not need wings like an airplane. This is how a rocket works. It is not made of rubber like a balloon, of course. It is made of metal. The metal must not be heavy but it must be very strong. There is gas inside the rocket which is made very hot. When it rushes out of the end of the rocket, the rocket is pushed up into the air.
Rockets can fly fat out into space. Rockets with men inside them have already reached the moon. Several rockets, without men inside them, have been sent to other worlds much father away. One day rockets may be able to go anywhere in the space.
36. What color is the sky()？
A. It is blue .
B. It is white.
C. It is grey.
D. It has no color.
37. When an airplane flies too high()？
A. the air will be too thin to support its wings
B. the air will become thicker
C. the air will exert pressure on it
D. the air will disappear in no time
38. A rocket can fly to the moon because ().
A. it looks like a balloon
B. it is much lighter than an airplane
C. it doesn’t have wings
D. it works like an untied balloon
39. Which of the following statements about a rocket is NOT true()？
A. It can fly when there is no air.
B. It can fly without wings
C. It is made of strong metal
D. it is propelled by burning gas inside it.
40. A rocket is pushed up into the air when ().
A. hot gas rushes out of its head
B. it is powered by gas
C. hot gas rushes out of its bottom
D. hot gas rushes out of its neck.
第2题
A．Book a hotel room.
B．Book an air ticket.
C．Order a table.
D．Make an appointment with the travel agent.
第3题
A．Because he got to the airport on time.
B．Because he escaped an air crash.
C．Because the taxi didn't arrive.
D．Because the engine of his car wouldn't start.
第4题
What does the man mean？
A．The air in the city is better than in the country．
B．The air in the country is better than in the city．
C．He wants to live in town．
第5题
People should be able to come to a decision about ions in the air if they ______.
A．note their own reactions
B．move to a healthier area
C．observe domestic animals
D．watch how wealthy people behave
第6题
A．Because she forgot to turn up the air conditioner.
B．Because she forgot to turn on the air conditioner.
C．Because the air conditioner was broken.
D．Because she wanted to save electricity.
第7题
How is food for plants made？ Food for plants is made______
A.from water
B.from the air in the sky
C.from the soil
D.from water, things in the soil and air, sunlight
第8题
When did Mrs. Green usually find the air in the room terrible？
A．During TV time.
B．During the meeting.
C．During the dinner time.
D．During the day time.
第9题
Why does the woman want to go to the country？
A．Because she wants to enjoy the fresh air there.
B．Because the scenery is beautiful.
C．Because she needs peace and quiet.
D．Because she doesn't like to stay with her husband.
第10题
What will be one effect of the new biotechnology on plants？
A．They will grow anywhere in the world.
B．Some will be able to grow in salty soils.
C．They will become poisonous to pests.
D．Using nitrogen from the air they will be able to cress fertilize.
