贫穷常常导致债务和绝望的恶性循环。

Poverty often leads to ___a ___vicious ___circle of debt and despair.

缺乏教育造成了贫困的恶性循环。

The lack of education creates ___a ___vicious ___circle of poverty.

当压力导致失眠，而失眠又增加压力时，这就是一个恶性循环。

When stress causes insomnia, which in turn increases stress, it's ___a ___vicious ___circle.