[单项选择]Many of the world’s pollution problems have been caused by the crowding of large groups of people into the cities. Supply for the needs of the people leads to further pollution by industry. If the rapid increase in human population continues at the present rate, there may be much greater harm. Some scientists speak of the increase in numbers of people as "population pollution".
About 2,000 years ago, the world population was probably 250 million. It reached a billion in 1850. By 1930, the population was two billion. It was three and a half billion in 1988. It is expected to double by the year 2000. If the population continues to grow at the same rate, there would be 25 billion people in the world a hundred years from now!
Man has been using the earth’s resources more and more rapidly over the years. Some of them are almost gone. Now many people believe that man’s greatest problem is how to control population, in time to come, if the present rate of increase continues. Already
A. city pollution
B. population pollution
C. countryside pollution
D. industry pollution

[单项选择]Many of the world’s pollution problems have been caused by the crowding of large groups of people into the cities. Supply for the needs of the people leads to further pollution by industry. If the rapid increase in human population continues at the present rate, there may be much greater harm. Some scientists speak of the increase in numbers of people as "population pollution".
About 2,000 years ago, the world population was probably 250 million. It reached a billion in 1850. By 1930, the population was two billion. It was three and a half billion in 1988. It is expected to double by the year 2000. If the population continues to grow at the same rate, there would be 25 billion people in the world a hundred years from now!
Man has been using the earth’s resources more and more rapidly over the years. Some of them are almost gone. Now many people believe that man’s greatest problem is how to control population, in time to come, if the present rate of increase continues. Already
A. fewer people moved from countryside to the cities
B. more people moved from countryside to the cities
C. industry developed less fast
D. many people moved to the cities without the development of industry

[单项选择]

Many of the world’s pollution problems have been caused by the crowding of large groups of people into the cities. Supply for the needs of the people leads to further pollution by industry. If the rapid increase in human population continues at the present rate, there may be much greater harm. Some scientists speak of the increase in numbers of people as "population pollution".
About 2,000 years ago, the world population was probably 250 million. It reached a billion in 1850. By 1930, the population was two billion. It was three and a half billion in 1988. It is expected to double by the year 2000. If the population continues to grow at the same rate, there would be 25 billion people in the world a hundred years from now!
Man has been using the earth’s resources more and more rapidly over the years. Some of them are almost gone. Now many people believe that man’s greatest problem is how to control population, in time to come, if the pre
A. fewer people moved from countryside to the cities
B. more people moved from countryside to the cities
C. industry developed less fast
D. many people moved to the cities without the development of industry

[填空题]Pentagon. Many have been held for more than three years and the______.

[单项选择]The history of modem pollution problems shows that most have resulted from negligence and ignorance. We have an appalling tendency to interfere with nature before all of the possible consequences of our actions have been studied in depth. We produce and distrobite radioactive substances, synthetic chemicals and many other potent compounds before fully comprehending their effects on living organisms. Our education is dangerously incomplete.
It will be argued that the purpose of science is to move into unknown territory, to explore, and to discover. It can be said that similar risks have been taken before, and that these risks are necessary to technological progress.
These arguments overlook an important element. In the past, risks taken in the name of scientific progress were restricted to a small place and brief period of time. The effects of the processes we now strive to master are neither localized nor brief. Air pollution covers vast urban areas. Ocean pollutants have bee
A. Unconcerned.
B. Humorous.
C. Serious.
D. Exaggerated.

[单项选择]The history of modern pollution problems shows that most have resulted from negligence and ignorance. We have an appalling tendency to interfere with nature before all of the possible consequences of our actions have been studied in depth. We produce and distribute radioactive substances, synthetic chemicals and many other potent compounds before fully comprehending their effects on living organisms. Our education is dangerously incomplete.
It will be argued that the purpose of science is to move into unknown territory, to explore, and to discover. It can be said that similar risks have been taken before, and that these risks are necessary to technological progress.
These arguments overlook an important element. In the past, risks taken in the name of scientific progress were restricted to a small place and brief period of time. The effects of the processes we now strive to maste
A. the nature of scientific progress.
B. the relationship between the progress of science and pollution.
C. certain factors that harm the circumstance.
D. the awareness of our responsibility to environment.