单选题 31. To save the Amazon rain forest from destruction, it is necessary to find a commercial profitable alternative to logging. Harvesting the fruits and nuts of the rain forest, however, is not a good alternative. To make harvesting commercially profitable, the ecological interrelationships of rain forest organisms would have to be transformed or destroyed.
Which of the following, if true, gives the strongest support to the argument above? ______

A、 Market research surveys have established that over 76 percent of the consumers who regularly purchase fruits and nuts harvested from a rain forest are not aware of the origin of those fruits and nuts.
B、 The current level at which nuts in the Amazon rain forest are being harvested is already causing starvation among many species of birds and mammals that would otherwise have eaten the nuts.
C、 Some companies harvesting rain forest fruits and nuts impose on their commercial clients a 5 percent environmental fee to restore logged areas in the rain forests.
D、 Indigenous peoples in the Amazon rain forest receive only a subsistence-level income for harvesting nuts and for logging hardwood trees.
E、 The harvesting of plant material for poisons, medicines, or foods has been part of the traditional culture of the rain forest peoples and has not noticeably damaged the rain forest.

【正确答案】 B

【答案解析】 B：该选项用鸟类和哺乳动物饿死来进一步加强破坏雨林生态这一结论，属于“直接加强结论”，正确。
A：原文讨论的是收割果子和破坏雨林之间的关系，与消费者是否知道它们的来源无关，不选。
C：征收环境费用来恢复雨林，说明在改善生态，削弱原文，不选。
D：该选项只能说明伐木和收割果子对当地人收入产生的影响，与生态关系无关，不选。
E：不会对雨林造成破坏，削弱原文结论，不选。