专业外语作业翻译

1、Fast and slowThis book will answer lots of questions that you may have about fast and slow.But it will also make you think for yourself.Each time you turn a page, you will find an activity that you can do yourself at home or at school. You may need help from an adult.Why do some things happen very f

2、ast, while others take much longer?Why can a train move faster than a bicycle, a rocket faster than a car?Moving fastSometimes it is important to move a long distance in a short time. To do this, you must move fast. Can you think of some things that move fast?Did you know?Another word for fast is ra

3、pid（adj.快速的; 摄感光快的; 险峻的;）. Parts of some rivers are called rapids, where the water moves very fast.Winning a raceIn a race, the fastest person usually wins.The people in this race have to push their wheels to move along（使）往前走， （使）走开;）.The harder they push the faster they will go.Fast animalsThese gi

4、raffes usually walk slowly on their long legs.But they can run very fast if they are chased by a lion.Now try thisOne way to make things go fast is to roll them down a slope.You will needA marble(n.大理石; 大理石制品; 弹子游戏; 理智，常识;), a tray(n.盘子; 托盘; 浅盘; 满盘; ) or a large pi

5、ece of cardboard.1 Hold one end of the tray above the table to make a slope(n.斜坡; 斜面; 倾斜; 斜率; ).2 Roll the marble down the slope - do not push the marble. Does the marble go faster if you make the slope higher?20122953 黄俊添Moving slowlyThings that move slowly take a long time to g

6、o a short distance. Children who are learning to walk move more slowly than adults do.Did you know?Some people have slow bicycle races. The idea is to ride your bicycle as slowly as possible without falling off.Slow walkerThis baby is learning to walk. To begin with, she takes small steps and moves

7、very slowly. As she grows up, she will take bigger, faster steps.Heavy and slowThe tortoise moves very slowly.It does not need to move fast, because it has a strong shell to protect it from predators(n.食肉动物).Now try thisSlow people move less far than faster people in the same time,You will needA fri

8、end.1 Stand next to your friend in a large room or garden,2 Now both walk forwards at the same time. You should walk slowly while your friend walks more quickly.3 Walk for about ten seconds, and see who has moved further.Measuring speedThe speed of something tells you how fast it is moving. A car mo

9、ving at a steady(adj.稳定的，不变的; 镇定的，沉着的; 坚定的;) speed of 40 kilometres per hour would travel40 kilometres in an hour.Did you know?Borzoi dogs can run very fast. They were bred(v.生育( breed的过去式和过去分词 );) to hunt wolves in Russia.Borzoi means 'speed' in Russia.How fast?This herd of zebra

10、walks about five kilometres every hour.This means that the speed of the herd is five kilometres per hour.20122953 黄俊添How long?This is a stopwatch. It is being used to measure how long a sprinter takes to run 200 metres. The faster the sprinter(n.短跑运动员，短距离全速奔跑者;) runs, the less time she will take.Now

11、 try thisA speedometer(机示速器，速度计) shows how fast a car moves. You can make a speedometre of your own.You will needA piece of paper(15 centimetres by 2 centimetres), a drinking straw sticky tape, a wooden skewer(n.串肉杆; 烤肉叉子; 叉状物; 针状物;).1 Tape the paper to the straw, so that it hangs dow

12、n, and push the skewer through the straw.2 Hold one end of the skewer and walk along. The faster you walk the higher the paper will swing up.BE SAFE!Skewers have a pointed end.Speeding upWhenever something moves faster, it speeds up. It needs a push or a pull to do this.Some things speed up by thems

13、elves, as gravity pulls them down a hill.Did you know?Downhill skiers can reach speeds of more than 100 kilometres per hour as gravity pulls them downhill.Push it!These people are pushing a bob sleigh(n.雪橇; ) to make it go faster. Once it is moving, the people will jump inside the bob sleigh, a

14、nd it will slide very fast on the ice.Faster and fasterAs it moves downhill, this bicycle moves faster and faster, pulled down the hill by gravity. At the bottom, the rider must use the brakes(n.制动器( brake的名词复数 ); 闸; 刹车; 阻力;) to slow down. Now try thisWhen you exercise, you heart beat

15、 speeds up.1 Touch a finger to the side of your throat, near the front.2 You should feel a movement every time your heart beats.3 Run or skip around for a few minutes. Feel you pulse(n.脉搏;) again. Is it faster or slower?20122953 黄俊添Slowing downHow can you make something move more slowly? If it is a

16、car or a bicycle, you simply use the brakes. Most things slow down by themselvesDid you know?Brakes on a bicycle pull on the wheels by rubbing against them. This helps to stop the bicycle.Air brakesThis is a space shuttle(n. 航天飞机;). It moves very fast. To slow down, the pilot uses a parachute(n

17、.降落伞; ). The parachute pulls on the shuttle and slows it down.Large wingsTo slow down, birds hold out their wings. The wings act like parachutes and slow the bird's speed.Now try thisA bicycle has brakes to slow it down. You can see how the brakes work.You will needA pencil, a circle of car

18、d about 10 centimetres across. 1 Ask an adult to push the pencil through the middle of the card.2 Hold the pencil in one hand and spin(n.旋转的行为;) the card with the other.3 Grasp the spinning card gently with a finger and thumb. It will slow down.Moving on landA car needs an engine to start it moving,

19、 and to keep it going. In the same way, fast animals must have strong muscles to push themselves along.Did you know?At full speed, an emu(n.鸸鹋（产于澳洲的一种体型大而不会飞的鸟）; ) can run as fast as the fastest athlete, about 45 kilometre per hour.Big jumperKangaroos move across land quickly in huge jumps. Som

20、e jumps are as long as 12 metres.20122953 黄俊添Long legsUnlike most birds, this emu cannot fly. Instead, it runs along the ground on its long, strong legs.Now try thisFind out how far you can jump.You will needA tape measure, a short, straight stick.1 Place the stick on the grass and stand behind it.2

21、 Now, jump as far forwards as you can, and stand still.3 Ask an adult to measure the distance from the stick to your feet. Is it as far as 12 metres?Moving in waterIf you have ever tried to walk quickly through the shallow end of a swimming pool, you will know that it is quite difficult. The animals

22、 that live in water have different ways of moving around.Did you know?One of the fastest animals in water is the flying fish.When it is moving fast, it sometimes leaps up(跳起来) out of the water into the air.Fast swimmerSeals like this one need to swim fast to catch fish. Their streamlined(流线型的) shape

23、 and powerful tail mean that they can swim fast underwater.Swimming slowlyThis jellyfish(n.水母; 海蜇) spends much of its time drifting in the water. It feeds on tiny sea creatures which drift towards it.Now try thisStreamlined shapes move more quickly through water than other shapes.You will needT

24、wo tall glasses, water, modelling clay(雕塑黏土;).1 Break off two small lumps of modelling clay. Make one smooth and pointed and the other a very rough shape.2 Fill the glasses nearly to the top with water.3 Drop both shapes into the water at the same time. Which shape moves faster?20122953 黄俊添Moving th

25、rough airMost birds fly through the air by flapping their wings. Birds use their wings to go faster and slower, or to change direction.Did you know?The spine-tailed swift(刺尾雨燕) can fly at a speed of about 10 kilometres per hour, faster than many cars travel.Falling slowlyIf you jumped out of an aero

26、plane, you would fall faster and faster. You can slow down by wearing a parachute.Faster and fasterLarge birds have to move fast before they can take off. Swans use their webbed(adj.有蹼的; 生蹼;) feet to move over the water fast.Now try thisMake your own parachute.You will needModelling clay, a han

27、dkerchief, four 20 centimetre pieces of string.1 Tie one end of each piece of string to a corner of the handkerchief.2 Press the free ends of the string into the modelling clay.3 Stand on a chair and hold two corners of the handkerchief. Let go of the parachute.Fast machinesPeople have made machines

28、 that travel on land, in water and in the air. Fast-moving machines must have powerful engines, and most have a streamlined shape.Did you know?The huge engines of a jumbo( 大型喷气式客机;) jet push it through the air at high speed. If it did not move fast, it would fall from the sky.Fast carLook at th

29、e shape of this car. As it moves along the road, air passes easily over it, and it can move very fast.20122953 黄俊添Speed boatNearly all boats are pointed（adj.尖的，尖锐的;） at the front. This makes them streamlined and helps them to move at high speed through the water.Now try thisYou can see for yourself

30、how important it is to have a streamlined shape.You will needA large umbrella.1 Open the umbrella and hold it out in front of you.2 Move forwards as quickly as you can.3 Close the umbrella, and try again. Is it easier to move now? Moving in spaceIn space there is no air, so things do not need to be

31、streamlined to move fast. To get into space, we need powerful rockets, which can travel very fast.Moon walkingAstronauts walk on the Moon with large, slow steps. They weigh less on the Moon than they do on Earth, so they do not fall as quickly to the ground after each step.Did you know?Meteors（流星） a

32、re lumps of rock and dust moving very fast through space. When they meet the air around the Earth, they burn up.Lift-offRockets like this one need to travel more than 11 kilometres every second to get into space.Now try thisYou can make your own rocket.You will need A long balloon, A balloon pump(球囊

33、泵; ), tape, a straw, a long piece of string, a chair.1 Push the string through a 2 centimetre piece of straw. Tape one end of the string to a chair.2 Blow up the balloon, and hold the end closed.3 Tape the straw to the side of the balloon.4 Pull the string tight, and bring the balloon to the fr

34、ee end of the string. Let go of the balloon.20122953 黄俊添Too fast to seeOur eyes can see most things but some things happen too fast for us to see. Special photographs can show what happened.Did you know?Chameleons catch files on their tongues. The tongue moves too quickly for us to see without a spe

35、cial camera.Fast wingsA bees wings flap so fast that they appear as just a blur(模糊). In this special photograph you can see the bees wings.Moving picturesWhen you watch a film, you see many separate pictures shown quickly one after the other. The pictures change so fast that they seem to move.Now tr

36、y thisYou can see how very fast things can blur together.You will needA square of card, a pencil , sticky tape.1 Draw the outline of a head in the middle of one side of the card.2 In the middle of the other side of the card, draw a mouth, a nose and eyes.3 Tape the card to the pencil. Now hold the p

37、encil between your hands and twist(旋转，转动;) it quickly. You should see the whole face.Too slow to seeSame things happen so slowly that you do not notice them for a time. You cannot see a plant growing, but you know it happens.Did you know?The stars seem to move across the sky very slowly during the n

38、ight. This is because the Earth is turning.Making a valleyA valley like this takes millions of years to form. The land moves and changes very slowly as the weather and the river gradually wear away(磨损; 磨掉; 消逝; 衰退;) the rock.20122953 黄俊添Rotten appleMany foods, such as this apple, become rotten very s

39、lowly. The last of these photographs was taken several weeks after the first.Now try thisThe minute hand of a clock moves too slowly to see, but you can see it has moved after a few minutes.You will needA clock or watch with a minute hand (the long hand).1 Watch the minute hand. Can you see it move?

40、2 Keep watching for a few minutes. You will see that it has moved from where it was.Growing fast and slowlyMost plants and animals, including you, grow a little every day. Young creatures grow very fast. A seed grows quickly to become a young plant.Did you know?A starfish can slowly grow back(重新长出;) parts of its body that have been lost or damaged.Tall grass Bamboo is a type of grass. It can grow higher than a house. Bamboo can grow very fast-as much as 30 centimetres every day.Growing up fastYoung rabbits grow very fast.