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) from cars and trucks have dropped from 10.3 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 programs; today in 1995 there are about 6，600．Advanced lights，motors，and building designs have helped save a lot of energy and therefore prevented pollution．

Twenty-five years ago，there were hardly any education programs for environment．Today，it's hard to find a public school，university，or law school that does not have such a kind of program．"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 _______ environment 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 forty 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．

[三]

Passenger pigeons(旅鸽) once flew over much of the United States in unbelievable numbers． Written accounts from the 18th and 19th centuries described flocks(群) so