共用题干第三篇Preserve the EnvironmentTh

共用题干

第三篇

Preserve the Environment

Throughout history man has changed his physical environment in order to improve his way of life.
With the tools of technology he has altered many physical features of the earth.He has transformed
woodlands into farmland,and made lakes and reservoirs out of rivers for irrigation purposes or hydroelectric
power. Man has also modified the face of the earth by draining marshes and cutting through mountains to
build roads and railways.
However,man’s changes to the physical environment have not always had beneficial results.Today,
pollution of the air and water is an increasing danger to the health of the planet.Each day thousands of tons
of gases come out of the exhausts of motor vehicles;smoke from factories pollutes the air of industrialized areas
and the surrounding areas of countryside.The air in cities is becoming increasingly unhealthy.
The pollution of water is equally harmful.In the sea,pollution from oil is increasing and is killing enor-
mous numbers of algae（水藻）,fish and birds.The whole ecological balance of the sea is being changed.
The same problem exists in rivers.Industrial wastes have already made many rivers lifeless.
Conservationists believe that it is now necessary for man to limit the growth of technology in order to sur-
vive on earth.

According to the passage,pollution of the air and water is caused by__________. A:thousands of tons of gases coming out of the exhausts of motor vehicles B:the changes of the environment that technology has brought to man C:the increasing amount of oil that has been produced D:industrial wastes discharged into rivers