Every object has weight. But the center of its weight is not always in the middle of the object. If the top of an object is heavier than its bottom, it will fall over easily. We say that its center of gravity 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 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. lighter than B. heavier than C. no heavier than D. as heavy as
2.Please point out which box will not fall.
3.The main idea of the passage is _________.
A. why things fall over B. a low center of gravity
C. a high center of gravity D. that everything has weight
There was a time when I thought my dad didn’t know how to be a good father. I couldn’t 16 him ever saying the words “I love you.” It seems to me his only purpose in life was to say “ 17 ” to anywhere I wanted to go and anything I wanted to do, including getting a 18 . Some parents bought their kids cars when they got their driver’s licenses. Not my dad — he said that I’d have to get a job and buy my own.
So that is what I did. I got a job at a very nice restaurant and 19 every penny I could and when I had enough to buy my car, I did! The day I brought that car home, my dad was the first one I wanted to 20 it off to. “Look, dad, a car of my own. If you ever want a ride, you only need to pay me five dollars.” I offered with a smile.
“I see,” was all he said.
One day, there was something wrong with my father’s truck. So he needed a 21 to work. The sun wasn’t even up when we left the house, 22 it was already getting warm out. It was going to be a hot day. As my dad got out of my car, I 23 him, dressed in his work clothes, getting his 24 from the truck (车尾箱) of my car. Watching his sun-weathered face, and even from a distance I could tell there were 25 lines than I ever remembered being there before. I realized how hard my dad works for the family. My father is a cement finisher(水泥修整工).
Suddenly, it came up with me that he actually got down on his hands and knees to sweat over hot concrete(混凝土) to make a living for his family. And he did this day in and day out, 26 hot it got. Never, not once, had I heard him 27 about it. To him we were “worth” it. And never once did he ask us to pay for it.
When he closed the trunk, his tools set off to the side, he walked over to my window to 28 me five dollars. I rolled down the window and said “Good-bye, dad. Keep your five dollars. It’s my __29__. Don’t work too hard. I love you.”
His eyes met mine, then glanced away in the direction of his waiting tools, he 30 his throat(喉咙) and said, “Oh, and… me, too.”
1.A. like B. remember C. forget D. care
2.A. Sorry B. Yes C. No D. Well
3.A. car B. friend C. job D. present
4.A. spent B. earned C. kept D. saved
5.A. take B. put C. turn D. show
6.A. ride B. leave C. trip D. hurry
7.A. as B. although C. but D. since
8.A. helped B. followed C. left D. watched
9.A. tools B. clothes C. luggage D. bag
10.A. fewer B. more C. longer D. less
11.A. whatever B. whenever C. wherever D. however
12.A. talk B. complain C. ask D. speak
13.A. hand B. borrow C. lend D. take
14.A. help B. advice C. treat D. idea
15.A. cleaned B. wiped C. cleared D. felt
—Would you please tell me _____? — Sorry, you can turn to Mr Lee for help.
A. how long can man live without water
B. whether Yao Ming still played for Rockets
C. how I can keep myself safe from the flu
D. why did a serious accident happen
—Well, my sons take great interest in most of the food on the menu. —Thanks. _____?
—Yes, fried fish, beef, chips and cola, please.
A. Can I do for you B. At your service
C. What to follow D. Shall I take your order
—My cousin often has nothing for breakfast, _____ she?
— _____. Because she often gets up late and is afraid of being late for school.
A. has; Yes B. doesn’t; No C. does; No D. hasn’t; Yes
—Be quite, the head teacher Mr. Qian is coming.
—Don’t worry. It _____ be him. Mr Qian is much fatter.
A. mustn’t B. may not C. needn’t D. can’t
