这根绳子太松了，需要拉紧一些。

This rope is too ___slack and needs to be tightened.

现在是淡季，店里顾客很少。

It's the off-season, so business is ___slack at the shop.

老师批评他作业太马虎。

The teacher criticized him for being ___slack with his homework.

考试结束后，他彻底松懈下来。

After the exam, he completely ___slacked off.