What do you have to do?

你必须做什么？

You have to be very careful.

你必须非常小心。

You have to go to the city centre.

你必须去市中心。

You have to go to bed early tonight.

你今晚必须早睡。

You have to work for long hours.

你必须长时间工作。

You have to read this old story.

你必须读这个古老的故事。

You have to come early tomorrow.

你明天得早到。

You have to be fit to sail a boat fast.

你必须身体健康才能快速航行。

You have to keep your body very still.

你必须保持身体非常静止。

You have to take care of this to stay alive.

你必须照顾这个才能活下去。