他需要持续的监督。

He needs constant ___supervision.

除非在老师的监督下，否则学生不允许处理这些化学品。

Students are not allowed to handle these chemicals unless they are under the ___supervision of a teacher.

这个小家伙是专门为你建造的，这样你可以把你的孩子交给两位训练有素的救生员监督。

The little one was built especially for you, so that you can leave your children under the ___supervision of two well-trained lifeguards.