A.regulating
B.halting
C.interrupting
D.combating
According to the text, genetic engineering can be used to ______.
A.kill weeds through cross-breeding
B.make crops hardier
C.improve the yield and quality of most crops
D.make crops resistant to chemical fertilizers
Which of the following statements is NOT mentioned in the passage?
A. Malaria is under attack in a number of countries.
B. Some types of mosquitoes have become resistant to the current sprays.
C. New poisons have been put into wide use with the new science.
D. One of human's challenges is to win the campaigns against mosquitoes.