Before a new type of airplane goes into service, every part of it is tested again and again. But there are two tests that are more important than all the others.

The first is called the "tank test". A modem airplane must fly very high in the sky. Air must be pumped into the plane so that the passengers can breathe. The metal structure （结构）of the plane has to be very strong for this reason. When the plane is filled with air, the air presses against the skin of the plane inside. The pressure （压力） on a small window is like a huge foot that is try??ing to get out. If a small part of the plane were to fail, the plane would explode in the sky. To test the structure of the plane, the plane is lowered into a huge tank or container of water. Then it is filled with air. The pressure inside the plane is greater than it ever will be when it is high up in the air. Finally, there is an explosion. This does not cause so much damage inside the water tank as it would anywhere else. Engineers can discover which part of the plane has broken. Then that part is made stronger.

The most dangerous test happens when the new plane is going through test flights in the air. The test pilot must find out exactly what happens when the engines （发动机） are all shut off at once. The plane begins to fall like a stone. It is the pilot’s job to find out how he can get control of the plane again. These two tests are examples of how planes are made safe before they ever carry passengers.

68. By doing the "tank test", the engineers can find out _______.

       A. the amount of air in the plane

       B. the strength of the plane structure

       C. the pressure inside and outside the plane

       D. the power of the airplane engines

69. What will happen to the plane under the "tank test"?

       A. It will be broken.                     B. It will be made stronger.

       C. It will be filled with water.                   D. It will be tested by pilots,

70. According to the text, why are test flights most dangerous?

       A. The plane may explode in the air.           

       B. The pilot may lose control of the plane.

       C. The engines may be damaged.              

       D. Too much air may get into the plane.

71. What might be the most suitable title for the text?

       A. Two Important Tests on Airplanes

       B. The Importance of Flying Safely

       C. The Danger of Testing Airplanes

       D. How Airplanes Are Made and Tested

 The hole in the earth's protective ozone layer（臭氧层）won't repair itself until about two decades later than had been expected, scientists announced.

The ozone layer blocks more than 90 percent of the sun's ultraviolet radiation（紫外线辐射）, helping to make life on Earth possible. For many dacades, ozone was depleted（削减） by chlorine and bromine gas in the air. A hole in the ozone layer formed over the Southern Hemisphere.

Computer models had forecast that the hole would fill back in by 2050. An improved computer model forecasts the recovery won't occur until 2068. The model, fed with fresh data from statellites and airplanes, was supported by the fact that it accurately reproduced ozone levels in the Antarctic stratosphere（平流层）over the past 27 years.

The ozone hole is actually more of a broad region with less ozone than ought to occur naturally. It is not limited to Antarctica, as is often believed.

Over areas that are farther from the poles like Africa or the US, the levels of ozone are only three to six percent below natural levels. Over Antarctica, ozone levels are 70 percent lower in the spring. This new method allows us to more accurately estimate（估计）ozone-depleting gases over Antarctica, and how they will decrease over time, reducing the ozone hole area.

Paul Newman, a scientist,said that the ozone hole has not started to become smaller as quickly as expected. They figure it will not become much smaller until 2018, after which time the recovery should proceed more quickly. And the hole will not be filled in again until 2065.

1.According to the passage, the ozone layer _______

2.The improved computer model is believable because _________

3.The underlined word “they” in the fifth paragraph refers to ________

We are all interested in equality, but while some people try to protect the school and examination system in the name of equality, others, still in the name of equality, want only to destroy it.
Any society which is interested in equality of opportunity and standards of achievement must __1  test its pupils. The standards may be changed — no examination is 2  — but to have no tests or examinations would mean the end of equality and of standards. There are groups of people who oppose this view and who do not 3 either in examinations or in any controls in school or on teachers. This would mean everything would depend on 4  since every pupil would depend on efficiency, the values and the purpose of each 5  .
Without examinations, employers will look for employees from the 6  respected schools and from families known to them – a form of favoritism will replace equality. At the moment, the bright child from an ill-respected school can show certificates to prove he is _7  for a job, while the lack of a certificate indicates the unsuitability of a 8  child attending a well-respected school. This defense of excellence and opportunity would disappear if examinations were 9  , and the bright child from a poor family would be a prisoner of his or her school’s reputation, unable to 10 for employment with the child from the 11__ school.
The opponents of the examination system suggest that examinations are an 12  force because they show differences between pupils. According to these people, there must be no special, __13 or academic class. They have even suggested that there should be no form of difference in sport or any other area: all jobs or posts should be filled by unsystematic 14  . The selection would be made by people who themselves are 15  selected by some computer.

We are all interested in equality, but while some people try to protect the school and examination system in the name of equality, others, still in the name of equality, want only to destroy it．

Any society which is interested in equality of opportunity and standards of achievement must regularly test its pupils．The standards may be changed because no examination is perfect, but to have no tests or examinations would mean the end of equality and of standards．There are groups of people who oppose this view and who do not believe either in examinations or in any controls in schools or on teachers．This would mean that everything would depend on luck since every pupil would depend on efficiency, the values and the purpose of each teacher．Without examinations, employers will look for employees from the highly respected school? And from families known to them, a form of favouritism will replace equality．At the moment, the bright child from an ill-respected school can show certificates(毕业证） to prove he is suitable for a job, while the lack of certificate indicates the unsuitability（不合适）of a dull child attending a well-respected school．This defense of excellence and opportunity would disappear if examinations were taken away, and the bright child from a poor family would be a prisoner of his school's reputation, unable to compete for employment with the child form the favoured school．

The opponents（反对者）of the examination system suggest that examinations are an evil force because they show differences between pupils．According to these people, there must be no special, different, academic class．They have even suggested that there should be no form of difference in sport or any other area: all jobs or posts should be filled by unsystematic selection．The selection would be made by people who themselves are probably selected by some computer．

1.The underlined word "favouritism" in paragraph 3 is used to describe the phenomenon that ___．

A．bright children also need certificates to get satisfying jobs．

B．children from well-respected schools tend to have good jobs

C．poor children with certificates are favoured in job markets

D．children attending ordinary schools achieve great success

2.What would happen if examinations were taken away according to the author?

A．Schools for bright children would lose their reputation．

B．There would be more opportunities and excellence．

C．Children from poor families would be able to change their schools．

D．Children's job opportunity would be affected by their school reputation．

3.The opponents of the examination system will agree that____．

A．jobs should not be assigned by systematic selection

B．computers should be selected to take over many jobs

C．special classes are necessary to keep the school standards

D．schools with academic subjects should be done away with

4.The passage mainly focuses on ____．

A．schools and certificates                   B．examinations and equality

C．opportunity and employment              D．standards and reputation

D
We are all interested in equality, but while some people try to protect the school and examination system in the name of equality, others, still in the name of equality, want only to destroy it.
Any society which is interested in equality of opportunity and standards of achievement must regularly test its pupils. The standards may be changed—no examination is perfect—but to have no tests or examinations would mean the end of equality and of standards. There are groups of people who oppose this view and who do not believe either in examinations or in any controls in school or on teachers. This would mean that everything would depend on luck since every pupil would depend on the efficiency, the values and the purpose of each teacher.
Without examinations, employers will look for employees from the highly respected schools and from families known to them－a form of favoritism will replace equality. At the moment, the bright child from an ill－respected school can show certificates to prove he or she is suitable for a job, while the lack of certificate indicates the unsuitability of a dull child attending a well－ respected school. This defense of excellence and opportunity would disappear if examinations were taken away, and tile bright child from a poor family would be a prisoner of his or her school's reputation, unable to compete for employment with the child from the favored school.
The opponents(反对者) of the examination system suggest that examinations are an evil force because they show differences between pupils. According to these people, there must be no special, different, academic class. They have even suggested that there should be no form of difference in sport or any other area: all jobs or posts should be filled by unsystematic selection. The selection would be made by people who themselves are probably selected by some computer.
53．The underlined word "favoritism" in paragraph 3 is used to describe the phenomenon that_____.
A．bright children also need certificates to get satisfying jobs
B．children from well－respected schools tend to have good jobs
C．poor children with certificates are favored in job markets
D．children attending ordinary schools achieve great success
54．What would happen if examinations were taken away according to the author?
A．There would be more opportunities and excellence.
B．Schools for bright children would lose their reputation.
C．Children from poor families would be able to change their schools.
D．Children's job opportunity would be affected by their school reputation.
55．The opponents of the examination system will agree that ________.
A．jobs should not be assigned by systematic selection
B．computers should be selected to take over many jobs
C．special classes are necessary to keep the school standards
D．schools with academic subjects should be done away with
56．The passage mainly focuses on________.
A．schools and certificates                                B．examination and equality
C．opportunity and employment                       D．standards and reputation