三、派生:
由一个词根加上前缀 或后缀构成另外一个词。
1.表示否定意义的前缀
disdishonest, dislike in-, ig-, il, im, ir, incapable, inability, ignoble, illegal, impossible, immoral, irregular mismisunderstand mislead nonnonsense ununable, unemployment anti-, antantiknock( 防震), antiforeigner,(排外的)
Practice (III):
Fill in the blanks with proper words.
development With the (1)____________ (develop) of industry, air pollution is and getting more (2)________ more serious. In Beijing, many people of suffer different kinds of illnesses because (3)_______ air pollution. by Air pollution is caused (4)_____ the following reasons: about half of the problem is caused by vehicles. There are more and more cars, out buses on the roads, and they give (5)______ poisonous gases. 25%of factor air pollution is caused by factories. Another (6)________ (fact) is the harm but smokers. Smoking not only does (7) ______ to their health(8)____ pollution also to others. Besides these, about 10% of air (9) ________ is caused by other reasons. against We should take some measures to fight(10)________ pollution. New fuel can be used to replace gas. We can plant more trees. If everybody realizes the importance of environment and does something to stop the problem will be solved.