题目内容
Every object has weight．But the center of its weight is not always in the middle of the object．If the top of ail object is heavier than its bottom (底部)，it will fall over easily．We say that its center of gravity (重力) is high．But if the bottom is heavier, it won’t fall easily, Then we say that its center of gravity is low．
Look at the first picture．This empty box must fall over, because its center of gravity (C) is not above the line of its bottom (AB)．
Now look at the second picture．There is some heavy iron (铁) in the bottom of this box．It will not fall，because its center of gravity is above its bottom．
1.If the bottom of an object is its top，it will fall over easily．
A．1ighter than B．heavier than
C．no heavier than D．as heavy as
2.Please point out which box will not fall．
3.The reason why the Leaning Tower of Pisa does not fall is that ．
A．the top of the tower is heavier than its bottom
B．the bottom of the tower is not heavier than its top
C．its center of gravity is still above the line of its bottom
D．its center of gravity is not above the line of its bottom
黄冈创优卷系列答案
请阅读下列短文。根据短文内容从每题所给的A、B、C、D四个选项中选出最佳选项。(每小题2分)
Henry | I like dogs. They are so cute. They play with us. How happy! |
Julia | I don't like dogs. Because they are scary. Some dogs hurt people. |
Nancy | Dogs are helpful! They help people with many things. Some dogs help do the housework. |
Andrew | I like dogs. They are clever. But my mother dislikes them. She thinks they are noisy. She only likes quiet and small animals. |
1.Who dislikes dogs?
A. Henry. B. Nancy. C. Andrew. D. Julia.
2.How many kids like dogs?
A. One. B. Two. C. Three. D. Four.
3.We can send to Andrew's mother.
A. a dog B. a rabbit
C. a tiger D. a panda
4.What kind of animals does Andrew's mother like?
A. Cute animals. B. Friendly animals.
C. Beautiful animals. D. Quiet animals.
5.Who has the same likes?
A. Henry and Nancy. B. Nancy and Julia.
C. Andrew and his mother. D. Julia and Andrew.
选词填空,并用其适当形式填空。（8分）
let off ; keep fit ; dress up as ; be good for ; try on be different from ; be on holiday ; take a walk |
1.Her hobbies ___________ mine .
2.My cousin __________ in the USA .
3.My mother usually ________ after meals .
4.A little meat a day ______________ your health .
5.Sometimes he ________ a doctor for fun .
6.Would you like _______ the pair of shoes ?
7.Most boys enjoy ________ fireworks on the Spring festival .
8.What sports must I do to _______ ? ---swimming .
