vicious circle

1. N-COUNT A vicious circle is a problem or difficult situation that has the effect of creating new problems that then cause the original problem or situation to occur again. 恶性循环

The more pesticides are used, the more resistant the insects become so the more pesticides have to be used. It's a vicious circle. 杀虫剂使用得越多，那些昆虫的抵抗力越强，因此就要使用更多的杀虫剂。这是一个恶性循环。