题目内容
You can’t see any object unless light from that object gets into your eyes.Some of the things you see give off light of their own。The sun,the stars,a lighted lamp are the examples that can be seen by their own light.But most of the things you see are not giving off light of their own.They are just reflecting(反射)light that falls on them from the sun or some other luminous bodies.The moon,for example,doesn’t give off any light of its own.It is not 1uminous.You see it because sunlight falls on it and some of the sunlight reflects on the earth.So moonlight is only second—hand sunlight.When you look at a book,it sends some of the light which fails on it to your eyes,and you see the book.If light could be kept out from where you’re so that there would be no light from the book to reflect.Then you couldn’t see the book even with your eyes wide open.Light travels so fast that the time in which it travels from the book you’re reading to your eyes is as short as if there were no time at time.Light reaches us from the moon,which is about 380,000 kilometres away,in only a little more than a second.
【小题1】You can see the book because________.
A.your eyes are close to it | B.it reflects some of the light |
C.it has light of its own | D.it is big enough to be seen |
A.闪光的 | B.看不见的 | C.发光的 | D.明亮的 |
A.The moon | B.The earth | C.The sun | D.The satellite of Dong Fong Hong |
A.300,000 | B.100,000 | C.400,000 | D.190,000 |
A.All the things you can see give off light. |
B.Light from the book is much faster than that from the moon. |
C.The moment you open your eyes,the light from the book travels to your eyes. |
D.Light travels so fast that there is no time for you to read. |
【小题1】B
【小题1】C
【小题1】C
【小题1】A
【小题1】C解析:
略
— You can’t imagine ________ great fun playing computer games is.
— Really? But it may cause you a lot of trouble.
A.what a |
B.how |
C.what |
D.how a |
No family wants its home to catch fire, but it's good to plan for a fire just in case (以防万一). Talk with your family about 36 to do if a fire starts. 37 should have a plan for getting out of the house. Be sure to choose a safe place to 38 after everyone gets away from the fire.
What should you do 39 there is a fire? First, 40 people know about the fire. Yell (叫喊) the word "fire". Knock on the walls with your hands.
Then 41 the door of your room. If the door is warm, don't open it. If it's cool, open it just enough to 42 . If you see fire or much smoke, close the door fast.
If you can't see fire or smoke, you can go out of the door. Shut the 43 behind you. That will slow down the fire. Now find a 44 out. Stay away from the smoke. The air is the 45 near the floor. So it 46 be the safest to crawl(爬)when you leave the house.
If you can't leave your room, close your door. Cover the crack (缝隙) under the door
47 clothing. Then open the window or 48 the glass with a chair. Crawl out, of the window 49 .If the window is high off the ground, 50 jump! Wave a towel out of the window, and yell for help. When you get out of the house, run to the place where you and your family chose to meet.
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