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

Make sure your hands are dirty.

Rub your hands together until you feel the heat of your hands.

Now, use soap and water to get your hands very slippery(滑的).

Try to make friction happen while your hands are slippery.

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?

Friction happens when you stop your fast running bike.

Ancient people made fire 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 text is most probably________________________.

A. a science report????????????? ????????????? ????????????? 　 B. a car advertisement

C. a rubbing introduction?????? D. a chemistry programme

2.What does the word “friction” in this text mean in Chinese????????

A.摩擦????????????? ????????????? B. 冷却??????? C. 膨胀????????????? ????????????? ????? D.震动

3.___________ is not an example of friction.

A. Bike riding????????????? B. Car driving??? C. Hands rubbing????????????? ? D.Friction discovering

4.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，用方框中所给单词的适当形式填空，每词限用一次。

The generation gap (代沟) has become a serious problem. It’s reported that some children may kill themselves if they 　1.　 with their parents. I think it is because they don’t have a good time with each other. Parents now spend more time in the office, so they don’t have much time to spend with their children. As time 　2.　 by, they both feel that they don’t have the 　3.　 topics to talk about. I think parents should spend more time with 　4.　, get to know them and understand them. And 　5.　 children, show your feelings to your parents. They really love you. So tell them your thoughts. In this way, you can have a better understanding of each other.

How pleased the emperor was _____ what the cheat said!

A. hearing 　? B. heard? 　 C. hear 　 D. to hear

—Here are two rice cards. Which one belongs to ______?

—Look. Here is my name. It must be ____. The other one is yours.

A. mine;me　????? B. me;mine????? ????????????? C. me;me?????? ????????????? D. mine;mine

下列字母中含有相同音素的是　　　　。

A. DCL         B. GFE            C. HCN          D. JAK