Seventy percent of the students in our school _____ from the countryside.

 A．is   B．a(chǎn)re   C．comes  D．a(chǎn)re coming

Have you ever been to___Great Hall of the People?

    A。a    B．a(chǎn)n    C．/  D．the

_______ （沒有人）of the students is able to work it out.

What pleasant surprise it is that our football won at last!

  I can’t say which wine is best—it’s a(n) _______ of personal taste.

A.affair    B.event    C.matter    D.variety

Having received___________ training of the MS. Company, he was offered important position in management.

   A. the;an        B. 不填;an      C. the;不填        D. a;a

The surprising experiment I am about to describe proves that air is all aroud you and that it proves down upon you．Air pressure is a wonderful force．When you swim underwater, you can feel water push down your body．The air all around you does the same．However, your body is so used to it that you do not notice this ．The pressure is caused by a layer of air called the atmosphere．This layer surrounds the Earth , extending to about five kilometers above the Earth’s surface．

The following experiment is an easy one that you can do at home．But make sure that you are supervised , because you will need to use matches．Now for the experiment！

What you need

·A hard-boiled egg without the shell

·A bottle with a neck slightly smaller than the egg

·A piece of paper

·A match

Metheod

1) Check that the egg will sit firmly on the neck of the bottle．

2) Tear the paper into strips and put the strips into the bottle．

3) Light the paper by dropping a burning match into the bottle．

4) Quickly sit the egg on the neck of the bottle．

Result

Astonishingly,the egg will be sucked into the bottle．Your friends will be amazed when you show them the experiment．But be careful when you handle matches．

Why it happened

 As the paper burns,it needs oxyen and uses up the oxygen(air) in the bottle．The egg acts as a seal in the neck of the bottle,so no more air can get inside ．This reduces the air pressure inside the bottle．The air pressure must equalize,so more air from outside must enter the bottle．The outside air pressure against the egg and then the egg is pushed into the bottle!The proves that air is all around and that it is pressing down on it．

When you do the experiment, why need you a person beside you?

     A．You couldn’t place the egg on the bottle by yourself．

     B．The egg needs to be shelled．

     C．You need to use matches．

     D．The bottle can’t sit firmly on the desk．

The purpose of doing this experiment is to prove ______．

       A．a(chǎn)ir pressure is a wonderful force

     B．water can push down your body when you swim underwater

     C．the air pressure is not equalized around us

     D．the earth is surrounded by a layer of air called the atmosphere

How did the egg put into the bottle？

       A．The oxygen inside the bottle suckde the egg in．

       B．It became solt without the shell．

       C．The neck of the bottle was wide enough．

       D．The outside air pressure forced it into the bottle．

The passage is ______．

     A．a(chǎn)n experiment report               B．a(chǎn) scientific story

     C．a(chǎn) research report                  D．a(chǎn)n interesting novel

All too often , a choice that seems sustainable（可持續(xù)的）turns out on closer examination to be problematic. Probably the best example is the rush to produce ethanol（乙醇）for fuel from corn . Corn is a renewable resource —you can harvest it and grow more, almost limitlessly. So replacing gas with corn ethanol seems like a great idea.

One might get a bit more energy out of the ethanol than that used to make it, which could still make ethanol more sustainable than gas generally, but that’s not the end of the problem. Using corn to make ethanol means less corn is left to feed animals and people, which drives up the cost of food. That result leads to turning the fallow land — including, in some cases, rain forest in places such as Brazil — into farmland, which in turn gives off lots of carbon dioxide（CO2）into the air. Finally, over many years, the energy benefit from burning ethanol would make up for the forest loss. But by then, climate change would have progressed so far that it might not help.

You cannot really declare any practice “sustainable” until you have done a complete lift-cycle analysis of its environmental（環(huán)境的）costs. Even then, technology and public policy keep developing, and that development can lead to unforeseen and undesired results. The admirable goal of living sustainable requires plenty of thought on an ongoing basis.

What might directly cause the loss of the forest according to the text?

A. The growing demand for energy to make ethanol.

B. The increasing carbon dioxide in the air.

C. The greater need for farmland.

D. The big change in weather.

The underline word “it” in the second paragraph refers to

A. the energy benefit               B. the forest loss

C. climate change                  D. burning ethanol

The author thinks that replacing gas with corn ethanol is    

A. impractical   B. acceptable    C. admirable    D. useless

What does the author mainly discuss in the text?

A. Technology.                   B. Sustainability.

C. Ethanol energy.               D. Environmental protection.

Catherine bought a postcard of the place she was visiting, addressed __________ to __________ and then posted it at the nearby post office.

A. it; her     B. it; herselff     C. herself; her     D. herself; herself

 It is none of your business __________ other people think about you. Believe yourself.

A. how    B. what   C. which   D. when