You have to learn

必须───must

Hospital operating instruments must be sanitary.───医院的手术器械必须是消过毒的.

We must do our work faster, and further better.───我们要把工作做得更加快一些, 而且要做得更加好一些.

From the reports of guns we knew that hunters must be nearby.───听枪声我们知道猎人必定在附近.

She asked the nurse how long her agony must last.───她问护士,她的极端痛苦要延续多久.

We must look beyond for signs of change.───我们应该把目光放远,看到变化的迹象.

We must decide between going home and staying at school during this winter vacation.───我们必须决定寒假期间是回家还是留在学校.

There must be something wrong with my left arm, which is asleep.───我的左臂发麻,一定出什么问题了.

This structure must be stable.───这种结构一定很稳固。

Why must she interrupt?───她为什么偏要打断呢？

A buxom widow must be either married , buried or shut up in a convent.───寡妇门前是非多.

If you want knwledge, you must toil for it.

You must lose a fly to catch a trout.

One must drink as one brews.

Children under 14 must be accompanied by an adult.

He that will thrive must rise at five.

We must make massive efforts to improve it.

The fish is rotten; you must not eat it.

A full cup must be carried steadily.

As the wind blows, you must set your sail.