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。

The more pesticides are used, the more resistant the insects become so the more pesticides have to be used. It's a vicious circle.

《柯林斯英汉双解大词典》

这可能导致我们进入一个恶性循环，即越来越多的植物和动物也濒临灭绝。

This can lead us on a downward spiral with more and more plants and animals becoming endangered as well.

youdao

这有可能成为一个恶性循环。

This can be a dangerous cycle.

youdao

And what we know is that very often we enter a downward spiral, a vicious cycle when we go into this narrow and constrict mode.

我们知道经常会进入下行螺旋，一个恶性循环，当我们进入狭窄收紧的模式。

哈佛公开课 - 幸福课课程节选