题目内容：
根据下列材料，回答题。
阅读部分第14题：The use of pesticides has contributed to
Aa change in the way ecologies are classified by agroecologists．
Ban imbalance in many ecologies around the world．
C the prevention of ecological disasters in some parts of the world．
Dan increase in the range of ecologies which can be usefully farmed．
参考答案：
答案解析：