词汇与问答题.docx

1、词汇与问答题Section B （9分）Directions: Complete the passage by using the proper words in the boxEach word can only be used onceNote that there is extra word in the boxAvaluable Binvolved Cmotivated DcontributeEconvenient Fservices Ggenerous HeffortsIrewards JcontactCommunities always have needs that are di

2、fficult to meetVolunteers, offering their _1_for free, can be a big helpThrough their unselfish _2_, they make caring for others an important part of lifeVolunteers are _3_ by a variety of things, but all of them agree that the _4_of charitable work can be preciousIt is easy to meet people with simi

3、lar interests, which is important to most volunteersVoluntary work is also a _5_way for teenagers to develop new skills and gain _6_experience, as well as make useful contactsThis can lead to employment opportunities in the futureIt is very simple if you want to get _7_. Start by making some enquiri

4、es at schoolYour teacher will be able to give you plenty of advice on whom to _8_if you want to _9_ some of your time to a voluntary organization1-9 FHCIE ABJDThe Earth has a force that pulls things toward itselfWe call this force gravityThis is something we live with all the time, and hardly ever t

5、hink about itBut it is a most important factor in rocket operation and must be overcome if we are to get anywhere in space, or off the ground at allTake the throwing of a ball as an exampleThe harder the ball is thrown, the faster and higher it will goWhat is the secret? Its speedIf we could throw t

6、he ball hard enough it would go up and up forever and never come downThe speed at which it would have to be thrown to do this is known as escape speedOf course, we cannot throw a ball hard enough because the speed, required to escape completely from the Earths gravity is seven miles per second, or o

7、ver twenty-five thousand miles per hourOnce escape speed has been reached by a spaceship, no further power is neededA rocket aimed at the Moon, for instance, will coast the rest of the way because the Earths gravity cannot then pull it back, and there is no air resistance in space to slow it downThi

8、s coasting is known as free fallThat does not mean the rocket is falling down towards the Earth but that it is traveling freely in space without the help of power, like a bicycle coasting downhillFree fall is an important feature of space travel：it would be impossible to carry enough oil to supply p

9、owered flight all the time1How fast will a rocket escape completely from the Earths gravity?2As there is always the Earths gravitational pull, people 3When a bicycle coasts downhill, it 4Why is it unnecessary to supply power for the flight in space all the time?1Seven miles per second/ Twenty-five thousand miles per hour2hardly ever think about it/ accept it without questioning it3does not need any further power4Because no further power is needed after the escape speed is reached