B. there are now more female than male smokers among high school seniors

C. high smoking rates are due to the increase in wealth

D. smoking at high school is from low socio-economic background

Since the first Earth Day in 1970, Americans have got a lot" greener" towards the environment．" We didn't know at that time that there even was an environment, let alone that there was a problem with it, "says Bruce Anderson, president of Earth Day USA.

　But what began as nothing important in public affairs has grown into a social movement. Business people, political leaders, university professors, and especially millions of grass-roots Americans are taking part in the movement. "The understanding has increased many, many times." says Gaylord Nelson，the former governor from Wisconsin, who thought up the first Earth Day.

According to US government reports, emissions（排放物） from cars and trucks have dropped from10.3 million tons a year to 5. 5 million tons. The number of cities producing CO beyond the standard has been reduced from 40 to 9. Although serious problems still remain and need to be dealt with, the world is a safer and healthier place. A kind of "green thinking "has become part of practices.

Great improvement has been achieved. In 1988 there were only 600 recycling programmes; in 1995 there were about 6,600. Advanced lights, motors, and building designs have helped save a lot of energy and therefore prevented pollution.

Many years ago, there were hardly any education programmes for environment. Today, it's hard to find a public school, university, or law school that does not have such a kind of programme. " Until we do that，nothing else will change! "says Bruce Anderson.

25.. According to Anderson, before 1970 Americans had little idea about

A. the social movement B. recycling techniques

C environmental problems D. the importance of Earth Day

26. Where does the support for environmental protection mainly come from?

A the grass-roots level B. The business circle

C. Government officials D. University professors

27. What have Americans achieved in environmental protection?

A. They have cut car emissions to the lowest

B. They have settled their environmental problems

C. They have lowered their CO levels in 40 cities

D. They have reduced pollution through effective measures

28. What is especially important for environmental protection according to the last paragraph?

A. Education B. Planning C. Green living D. CO reduction

A recent study, while showing a generally positive attitude toward science, also suggests a widespread worry that it may be "running out of control ". This idea is dangerous.

Science can be a force for evil(邪恶）as well as for good. Its applications can be channeled either way, depending on our decisions. The decisions we make, personally