They [DDT and other pesticides of its type] tend to be endlessly recycled in the food chains on which birds and animals and man himself are completely dependent.
A、The food chains for living creatures depend on the recycling of those chemicals.
B、The cycle of those chemicals in the food chains for living creatures never stops.
C、There is always a great influence of those chemicals on the food chains.
D、No living creatures can live those chemicals in their food.
【正确答案】：B
【题目解析】：此句的意思是它们（DDT和其他类型的杀虫剂）在食物链上不断地循环利用，鸟类和动物以及人都完全依赖于食物链。
