Passage Three:Questions 31 to 35 are based on the following passage.Brazil has become one of the developing world’s great successes at reducing population growth-but more by accident than design. While countries such as India have made joint efforts to reduce birth rates, Brazil has had better result without really trying, says George Martine at Harvard. Brazil’s population growth rate has dropped from 2.99% a year between 1951 and 1960 to 1.93% a year between 1981 and 1990, and Brazilian women now have only 2.7 children on average. Martine says this figure may have fallen still further since 1990, an achievement that makes it the envy of many other Third World countries. Martine puts it down to, among other things, soap operas (通俗电视连续剧) and installment (分期付款) plans introduced in the 1970s. Both played an important, although indirect, role in lowering the birth rate. Brazil is one of the world’s biggest producers of soap operas. Globo, Brazil’s most popular television network, shows three hours of soaps six nights a week, while three others show at least one hour a night. Most soaps are based on wealthy characters living the high life in big cities. “Although they have never really tried to work in a message towards the problems of reproduction, they describe middle and upper class values-not many children, different attitudes towards sex, women working,” says Martine. “They sent this image to all parts of Brazil and made people conscious of other patterns of behavior. and other values, which were put into a very attractive package.” Meanwhile, the installment plans tried to encourage the poor to become consumers. “This led to an enormous change in consumption patterns and consumption was incompatible (不相容的) with unlimited reproduction,” says Martine. 第31题：According to the passage, Brazil has cut back its population growth ________. A) by educating its citizens B) by careful family planning C) by developing TV programmes D) by chance