C

　　It is only during the last few years that man has generally realized that in the world of nature a balance exists between all forms of life. No living thing can exist by itself. It is part of a system in which all forms of life are joined together. If we change one part of the nature order, this will almost certainly bring about changes in some other part.

　　The cutting of forests reduced the supply of oxygen. The killing of weeds and insects by chemicals led to the wide-spread poisoning of animals and birds. The throwing of waste products into the ocean hurt life in the sea, while waste gases changed the chemical balance of the atmosphere and shut out some of the sun’s necessary life-giving rays.

　　And so we could go on adding more examples until in despair(绝望) we might feel like giving up the struggle to control these harmful human activities. Man is very clever at changing the world around him to satisfy his immediate needs, but he is not so clever at looking far ahead, or at thinking about what the future results of his action might be. Man may well destroy himself because of his silly action.

　　64. The first paragraph tells us that _____.

　　A. all living things in nature depend on each other

　　B. everything in nature can’t exist without the help of man

　　C. man has known the importance of the balance of nature for a long time

　　D. no living thing can live naturally

　　65. In the second paragraph the examples given are used to prove that _____.

　　A. all forms of life belong to a system in which all the parts can be changed for one another

　　B. it is only during the last few years that man has generally known the balance of nature

　　C. there are some living things which can exist by themselves without change

　　D. we can’t change one form of life without destroying the balance of nature

　　66. The last paragraph suggests that in order to get his immediate benefits(利益) _____.

　　A. man is always anxious to control his activities within limits

　　B. man is always too eager in planning for distant future

　　C. man often fails to think about their future results of his action

　　D. man often feels that he will have to give up in despair

　　67. Which of the following is true according to the passage?

　　A. Cutting down woods does little harm to human beings.

　　B. Man has to pay much more attention to the future results of his present action.

　　C. Oxygen comes from forests.

　　D. The passage tells us to try our best to get as much as possible immediately.

　　D

　　Scientists used to explore on the surface of the ocean. Now they are exploring below the surface, too. They want to know about ocean water and the plant and animal life deep in the ocean.

　　In 1934 the scientist William Beebe dived 3,000 feet below the surface in a hollow steel ball. In 1935 August Piccard dived 10, 330 feet. In 1960 his son Jean dived to a depth of 35,800 feet.

　　All these early dives were deep. But the divers could not stay down for very long. They had to come back up to the surface after a few seconds. Scientists needed to stay down longer to study life below the surface. Gradually they succeeded. Cousteau, a Frenchman, was able to keep men down to a depth of 36 feet for one month and to a depth of 90 feet for a week.

　　Now scientists are developing even better equipment. With this new equipment, men can stay below the surface for days or even weeks. In 1962 Cousteau set up a research station 35 feet below the surface. Then in 1964 he set up another station on the ocean floor of the Red Sea. This was the first undersea station to operate without help from the surface.

　　Many countries are now studying undersea living things. The former Soviet Union had an undersea laboratory in the Crimean Sea. The United States has a laboratory 50 feet down on the ocean floor off the Virgin Islands. In 1970 five men lived there for two weeks. Then a team of five women scientists stayed in the laboratory. Next came other teams of men. All were there to explore the ocean depths and to make plans for the use of its resources. Scientists hope to find enough mineral, vegetable, and animal wealth there to provide food for the entire world.

　　68. In order to _____, scientists are exploring below the surface of the ocean.

　　A. know about the ocean water deep in the ocean

　　B. know about the plant and animal life deep in the ocean

　　C. stay down longer to study life of the plant and animal below the surface

　　D. both A and B

　　69. Who made the deepest dive?

　　A. August Piccard 　　B. Cousteau 　　C. Jean Piccard 　　D. William Beebe

　　70. Who set up the first undersea station?

　　A. A Frenchman 　　B. An American 　　C. A Russian 　　D. The passage made no mention

　　71. Which of the following is true according to the passage?

　　A. Nobody can stay below the surface of the ocean.

　　B. The early divers could not stay below the surface of the ocean for very long.

　　C. The purpose of setting up the undersea laboratories is to make plans for the use of the resources in the ocean.

　　D. Up to now only five women scientists have stayed in the undersea laboratory.