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 dry. 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 too hot, touch the tires (轮胎) of the car before and after a short drive to see how much warmer they get from friction.

根据表格内容，选择正确答案。
【小题1】 You’d better make your hands                 to get heat when you rub them.

A．slippery

B．dry

C．wet

D．smooth

【小题2】 What does the word “friction” in this text mean in Chinese?

A．摩擦

B．冷却

C．膨胀

D．震动

【小题3】                        is NOT an example of friction.

A．Bike riding

B．Car driving

C．Hands rubbing

D．Friction discovering

【小题4】 What’s the last column (栏目)?

A．THINK IT OVER!	B．WHAT HAPPENED?
C．EVERYDAY ACTION:	D．WORK WITH PARENTS!

【小题5】This text is most probably                         .

A．a science report	B．a car advertisement
C．a rubbing introduction	D．a chemistry programme

Once, there was a wild donkey (驴) and a tame (驯养的) donkey.

  The wild donkey was thin and small. He spent his life in the ____. The grass on the hill was his food all the year around. Sometimes, he had to walk miles to find clean water and at night there was always ____ from lions. The tame donkey was much fatter and ____. During summer, the owner fed him grass while in ____, he was given corn and hay (干草) to eat. There was always clean water for him to ____ and at night he stayed inside safely.

  The wild donkey always wished he could live ____ the tame donkey.

  One day, the wild donkey was looking for grass on the hill. Looking down, he saw the tame donkey walking slowly along the road, ____ heavy wood. As he watched, the tame donkey stopped to eat some ____ by the roadside. Suddenly, his owner began to drive him with a ____.

  “I don’t want your way of life,” thought the wild donkey. “I see that you have to pay ____ for the food they give you.”

1.A. house     B. zoo     C. wild     D. river

2.A. danger     B. noise     C. drink    D. food

3.A. taller     B. shorter    C. weaker   D. stronger

4.A. spring     B. summer    C. autumn   D. winter

5.A. eat      B. smell     C. drink    D. feel

6.A. with      B. without    C. like     D. unlike

7.A. cutting     B. carrying   C. eating    D. burning

8.A. grass     B. meat     C. fish     D. water

9.A. stick      B. knife     C. fork     D. string

10.A. easy     B. easily     C. heavy    D. heavily

 

Do you ever find yourself getting really unhappy for almost no reason? Or suddenly feeling down without knowing why? Going from sadness to anger to joy in a matter of minutes can make many teens feel as though they're losing control. But why is the feeling so common among teens?
Maybe you're starting a new school and not able to see old friends as much. Getting good grades or wanting to be better in sports or other activities can be a concern (关注)for many teens. Being accepted by friends is important. Teens also may notice, for the first time, a sense of distance from parents and family. You may feel you want to be on your own and make your own decisions, but it can also seem a bit lonely at times.
Another important cause for mood swings is biology. When puberty begins, the body starts producing hormones（荷尔蒙）. These hormones cause physical changes in the body. But in some people, they also seem to cause emotional(情绪的)changes.
Here are some things you can do that might make those bad moods a bit easier to deal with.
Recognize you're not alone. Although not every teen experiences mood changes to the same degree, they are common.
Talk to people you trust. Friends can help each other by realizing that they're not alone in their feelings. Talking to parents is important, too. Parents can share their own experiences dealing with bad moods. Teachers are often good resources and a doctor can help to answer questions about development.
Get enough sleep. Though it can be hard to find enough time, getting enough rest is very important. Being tired can lead to more sadness.
Create. Taking part in some kinds of activities, like building something out of wood, or starting an art or music piece. Writing can help you organize and express your thoughts and feelings. Get your thoughts on paper. Do the same thing with paint, music, or other art forms. Put your feelings into your artwork.
【小题1】When puberty begins, many teens feel__________.

A．unhappy	B．angry
C．joyful	D．emotional

【小题2】The underlined word “puberty” in the passage probably means “       ”

A．成长期

B．青春期

C．情绪化

D．变化期

【小题3】 _______may not make some teens be in bad moods.

A．Study pressure

B．Getting good grades

C．The sense of distance from parents

D．Missing old friends

【小题4】It’s easier to deal with your mood changes by ___________.
①realizing they are common
②explaining your feelings to people you trust
③playing computer games
④being creative
⑤breaking school rules
⑥getting enough sleep

A．①②③④	B．①②③⑥
C．①②④⑥	D．①③④⑤

【小题5】The passage is mainly for ________.

A．parents	B．teenagers
C．teachers	D．doctors

从每题所给的选项中选出正确答案，补全短文。
Building a new house costs quite a lot of money. If you plan to   1  a house, your first step is to find a suitable (适当的 piece of  2 . You will probably try to find a sunny place, in a  3 situation  (位置), near stores and bus stops, not too  4  from your friends and the place where you work. Next you have to find an experienced (有经验的) builder, and together with the builder you will make a  5  . The builder will draw it. The builder will also   6  the cost of your house.
He will estimate (估计) the cost of the wood, the glass, and  7  that he must use in building the house. Later on, when he starts to build, his estimate must be right, because the    8   may change (变化), and many other things may happen between the time when he makes the estimate and the time when he builds the house.        9  the builder gives you his estimate, you may wish to change your plan. You may find that some of the things you wanted at first cost too much, or that you can   10  a little more and add something to your first plan.

【小题1】

A．but B．have C．build D．find

【小题2】

A．floor B．place C．land D．playground

【小题3】

A．faraway B．surprised C．pleased D．pleasant

【小题4】

A．near B．far C．close D．next to

【小题5】

A．map B．plan C．decision D．book

【小题6】

A．find out B．carry on C．work out D．work on

【小题7】

A．everything else B．nothing else C．else anything D．else something

【小题8】

A．color B．prices C．time D．house

【小题9】

A．When B．While C．Until D．Since

【小题10】

A．cost B．spend C．take D．pay for

Paul and Jason were brothers who lived and worked on neighbouring farms．For 35 years they farmed side by side，sharing machinery and goods as needed，without a single problem．
However，one autumn，things changed．It began with a tiny disagreement about a horse，which grew into a major difference．The difference led to angry words，followed by weeks of silence between the two brothers．
One morning there was a knock on Paul’s door．He opened it and saw a builder holding his toolbox．“I’m looking for a few days’work，”the builder said．“Are there any jobs here I could help with?”
“Yes，”answered Paul，extremely pleased to see the builder．“I do have a job for you．Look at that farm across the creek(小溪)．That’s my brother’s farm.That creek used to be a grass field，but last week my brother dug a path from the fiver and made the creek．But I’ll go him one better．See that pile of wood?1 want you to build me a fence，two metres tall，so 1 won’t need to see him anymore．”
The builder said thoughtfully．“I think I understand the situation and I'll be able to do a job that pleases you．”
Paul had business in town that day and left the builder to his work．When he returned，the builder had just finished his job．Paul was shocked．Instead of a fence there was a bridge，stretching from one side of the creek to the other．
As Paul stood on the bridge，staring in amazement，his younger brother Jason，came across，and took Paul’s hand．“You are a good man to have built this bridge after a11 I've done，”said Jason．
Then，Paul，with tears in his eyes，said to the builder who was packing his bag to go，“Thank you so much。Please stay．I have much more for you to do．”
“I’d love to．”the builder said quietly，“but，I have many more bridges to build.”
【小题1】What was the cause of the disagreement between the two brothers?

A．The digging of the creek．

B．A problem about a farm animal．

C．Who owned the field between the farms．

D．Who would pay for building the fence．

【小题2】The underlined expression“go him one better”in paragraph 4 means         ·

A．do something even worse	B．improve the situation
C．point out his mistake	D．help him out

【小题3】What do we know about the brothers?

A．They had been fighting for many years．

B．Their farms were not very successful．

C．They finally realized their mistakes．

D．They liked building bridges．

【小题4】Why did the builder build the bridge?

A．He needed a way to get across the river．

B．There was not enough wood for the fence．

C．He misunderstood Paul’s instructions．

D．He wanted to bring the brothers together．

【小题5】In what order did the following take place in the story?
a．The brothers stood on the bridge．
b．Jason dug the creek．
C．The brothers became angry with each other,
d．The builder asked for work．
e．Paul went into town．
A．b，c，e，d，a    B．c，b，d，e，a
C．b，e，c，a，d    D．c，d，b，a，e