Have you ever rubbed your hands together when they get cold? Why do we do that? We do that for friction. Friction happens when two things that aren’t very smooth rub together to make heat energy. The faster you rub two things together, the more friction ( and heat) you can make. Let’s discover friction!
WHAT YOU’LL NEED:·Soap ·Water· Your hands!
WHAT TO DO:
1. Make sure your hands are dirty.
2. Rub your hands together until you feel the heat of your hands.
3. Now, use soap and water to get your hands very slippery(滑的).
4. Try to make friction happen while your hands are slippery.
5. Please write down what has happened.
LET’S TALK!
Friction is an energy that happens when two things rub together. When friction happens, it makes heat! When your hands are slippery, they won’t make very much friction and your hands won’t get so hot.
DID YOU KNOW?
(1)Friction happens when you stop your fast running bike.
(2)Ancient people made fires by rubbing two pieces of wood together. Friction happened though they didn’t know it.
________?_________
Friction is everywhere. Have you ever noticed situations where friction is happening? If not, ask your parents to take you out in a car. If it is not hot, touch the tires(轮胎) of the car before and after a short drive to see how much warmer they get from friction.
1.This passage is most probably ____________.
A.a science report B.a car advertisement
C.a rubbing introduction D.a chemistry program
2.____________ is not an example of friction.
A.Bike riding B.Car driving C.Hands rubbing D.Friction discovering
3.What’s the last column(栏目)?
A.THINK IT OVER! B.WHAT HAPPENED?
C.EVERYDAY ACTION: D.WORK WITH PARENTS
根据短文内容,从各题所给的A、B、C、D四个选项中选出最佳选项。
Mr Wu is an English teacher. Last Monday at the beginning of class, he_______asked his students how their weekends had been. One girl said that she had spent a _______ weekend—she had her wisdom teeth pulled out and they still hurt. “Why do you always seem to be so happy, Mr Wu?” she asked.
The girl's question_______ Mr Wu of something he had read somewhere before. “Every morning when you get up, you have a _______ about how you want to get close to life that day,” Mr Wu said with a smile. “I choose to be cheerful.”
“And today is my _______ day,” he added.
“Why ?” The students’ eyes opened wide. The whole class were curious.
“This morning, I _______to school as usual. I only had to go another kilometer down the road when my e-bike broke down...”
“Your e-bike broke down and you are happy?” The students were _______. “What do you mean, Mr Wu?”
“My e-bike broke down a quarter before class, so I _______ it on the roadside, took my books, and_______down the road. It took me ten minutes to arrive at the school. I live eight kilometers away. My e-bike could have broken down ________ along the way. But it didn't. But, it broke down in the________ place—off the main road, within walking distance of here. I'm still able to teach my class, I'll be able to get it repaired after class ________and I can get back home on my e-bike. If my e-bike must break down ________, it couldn't be arranged(安排)in a better way.”
The students smiled. Mr Wu smiled back. Somehow, his story had ________ them. He was happy that they had a perfect chance to consider ________in a new way.
1.A.proudly B.cheerfully C.seriously D.angrily
2.A.busy B.satisfying C.terrible D.meaningful
3.A.reminded B.warned C.told D.thought
4.A.question B.task C.dream D.choice
5.A.awful B.faithful C.busy D.lucky
6.A.walked B.ran C.drove D.rode
7.A.surprised B.bored C.impatient D.nervous
8.A.repaired B.checked C.left D.found
9.A.rode B.walked C.drove D.skated
10.A.somewhere B.anywhere C.everywhere D.nowhere
11.A.middle B.dangerous C.perfect D.bad
12.A.hard B.secretly C.exactly D.rapidly
13.A.yesterday B.that day C.tomorrow D.today
14.A.hurt B.touched C.controlled D.worried
15.A.dream B.purpose C.wish D.luck
— Playing video games is really a waste of time.
— _________. There are more meaningful things to do.
A.I can’t agree more B.I hope so C.I have no idea D.I’m afraid not
—I promise that I will read English for half an hour every morning from now on, mum.
—Really? ________.
A.Every dog has its day
B.Practice makes perfect
C.Many hands make light work
D.Actions speak louder than words
—Would you like to spend summer holiday in the countryside?
—Oh, dear, I have been used to the life in the city. I think life here is _______.
A.more comfortable
B.less comfortable
C.the most comfortable
D.the least comfortable
—The light in his room is still on. Do you know _______?
—Maybe he wants to finish the DIY.
A.what’s she busy doing
B.why he stays up so late
C.if he is busy studying
D.when he will stop working