[单项选择] Biotechnology Biotechnology in one form or another has flourished since prehistoric times. When the first human beings realized that they could plant their own crops and breed their own animals, they learned to use biotechnology. The discovery that fruit juices fermented(发酵) in wine, or that milk could be converted into cheese or yogurt(酸乳酶) or that beer could be made by fermenting solutions of malt(麦芽) and hops(啤酒花) began the study of biotechnology. When the first bakers found that they could make a soft, spongy(多乳的) bread rather than a firm, thin cracker they we’’re acting as fledgling(缺乏经验的) biotechnologists. The first animal breeders, realizing that different physical traits could be either magnified or lost by mating appropriate pairs of animals, engaged in the manipulations of biotechnology. What then is biotechnology The term brings to mind different things. Some think of developing new types of animals. Others dream of almost unlimite
A. People made beer by fermenting solutions of malt and hops.
B. Bakers used flour and sugar to make a firm, thin cracker which is delicious.
C. Workers converted milk into cheese.
D. Animal breeders mated appropriate pairs of animals to magnify their traits.