You must drop back from vessel ahead of you.

你船必须拉开与前面船的距离。

Advise you drop back from vessel ahead of you.

建议你船拉开与前面船的距离。

In 20 minutes your blood pressure will drop back down to normal.

20分钟内你的血压将降至正常水平。

The early leaders drop back and allow others to make the running.

开始时领先的人纷纷落下，让别的一些人跑到了前头。

As soon as we reached the little village, we got the order to drop back.

我们刚到这个小村庄，就接到返回的命令。