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

短文填空  先通读下面的短文，然后根据短文内容和所给首字母，在空格内填入一个适当的单词，使短文意思完整。所填单词必须在答题卡标有题号的横线上完整写出。（本大题共10空，每空0.5分，共5分）

　In many countries, people t__________ 1. by car or by bike. They also get from place to place using p__________2.transport such as buses and trains. However, some people live in parts of the world where it is i__________3. to build roads. In these places, animals or other forms of transport have to be used.

　　It is difficult to w__________ 4. in snow but easy to ski over it. So in places like Alaska, people use skis. If they want to go faster, they get dogs to p__________ 5.them on sleds(雪橇). Riding a snowmobile(雪地摩托) is a more m__________6., but expensive way of getting around on snow.

　　In desert(沙漠) like the Sahara in North Africa, people s__________ 7.get around on camels. Camels survive w_________8. in the desert, not because they can s_________9.water in their bodies though! They can survive without water for two weeks and without f__________10.for up to a month. He can only go without water for about three to five days.

根据句子意思和单词的首字母提示写单词。

1.—Can you s         it?　—Yes．P-E-N-C-I-L，pencil．

2.My eraser is in my pencil c        ．

3.E         me，may I know your name?

4.This is my new c         game．

5.Please c         him at 010-68816881．

6.Is this your English b        ?

7.What’s this in E        ?

8.P         call Mary at 87322480．

9.Is this y         ruler?

10.That’s a nice w        ．

补全对话。

　　A: Hello, Tom. I can't 1． my pen. 2． you know where it is?

　　B: 3． . I don't know. 4． it in your pencil-box?

　　A: No, it 5．

　　B: What 6． is it?

　　A: It's red.

　　B: Don't 7． . Let me 8． you find it.

　　A: 9． you very much.

　　B: Look! 10． under your Chair.

　　A: Oh, it's my pen.