There are many ways of putting out a fire. You may have seen people put out burning cigarettes by stepping on them. Stepping on cigarettes shuts off the air and puts out the fire.
Many fires are put out with water. Water cools the materials that are burning. It helps make the fire die out. Some of the water is changed into steam when it strikes the hot fire. The steam keeps air from the fire and helps put it out.
Some fires can not be put out with water. Suppose a tank full of gasoline(汽油)is on fire. Gasoline is lighter than water. If you poured water into the tank of gasoline, the water would sink to the bottom of the tank. The gasoline would float on top of the water on the fire and flow over the edge of the tank. Then the fire would spread. Gasoline fires should be put out with sand or with chemicals of some kind, such as that used in some fire extinguishers(灭火器).
1. People often put out burning cigarettes by stepping on them. This is because .
A. the burning cigarettes are too hot to touch
B. it helps to stop smoking
C. it shuts off the air and makes the fire go out
2. According to paragraph 2, what will happen to the water if it is poured on the fire?
A. Some of the water will turn into steam and keep air from the fire.
B. Most of the water will flow away.
C. The water will be absorbed by the fire.
3. Gasoline fire should be put out .
A. with hot wate
B. with nothing but sand
C. with sand or chemicals
完形填空(共10小题;每小题2分,满分20分)
阅读下面短文,从短文后各题所给的A、B、C三个选项中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。
Many thousands of years ago,there are no houses such as people live in today. Men sometimes made their homes____so as to be safe from their____and wild animals;the leaves of the trees would keep the rain and sun____.
In cold areas,ancient people used ___their homes in caves. It was too cold and stormy to live in trees there.
As years went on,men____more about living in comfort and safety.They___their trees and caves and built houses of different materials___mud,wood or stones.
During the last hundred years,many new building materials and new methods of building____.People now live comfortably in a variety of houses.
____design or materials are used,the buildings should be bright,airy and comfortable. Human beings need sunlight and fresh,clean air in order to remain____.
1.A. in trees B.in rivers C.on the grass
2.A. friends B.neighbors C.enemies
3.A. in B.off C.down
4.A. make B.to making C.to make
5.A. saw B.learned C.recognized
6.A. came to B.went on C.left
7.A. according to B.for example C.such as
8.A. have been discovered B.were discovered C.had discovered
9.A. No matter where B.No matter what C.No matter when
10.A. active B.healthy C.happy
–On, no! There isn’t any sugar left.
--_________. I’ll buy some when I go into town.
A. Good idea B. Never mind C. Go ahead
He wasn’t _______ to join the army.
A. such old B. so old C. old enough
Tommy is the oldest boy and is taller than ___ boy in the class.
A. the other B. any other C. each
A Disneyland Park ________ in Shanghai Pudong New Area in the near future.
A.has been built B.will built C.will be built