can 和 must 作为情态动词，它本身不能用于被动语态，但它们后面所接动词可以用被动式。如：

▲can后接动词的被动式

No rules of universal application can be given. 订不出普遍适用的规则。

They can be trusted to some degree. 从某种程度上说他们是值得信任的。

In given conditions a bad thing can be turned into a good one. 在一定条件下，坏事可以变为好事。

In meetings she always takes the offensive before she can be criticized. 在会上，她总是不等别人批评她就先发制人。

A man’s character can be measured by the types of men with whom he associates. 一个人的品格可按与他结交者的类型来衡量。

This dictionary gives the meanings of words and also illustrates the constructions they can be used in. 本词典提供词义解释，并举例说明遣词造句的方法。

▲must后接动词的被动式

Glass must be treated carefully. 玻璃必须小心使用。

Children must be accompanied by an adult. 小孩须由成人陪同。

These chemicals must be tightly kept. 这些化学药品须密封保存。

Debts of blood must be paid in blood. 血债要用血来偿。

Application must be made this afternoon. 申请必须在今天下午提出。

The work must be done within the given time. 工作必须在规定时间内完成。

The job must be done exactly as she wants it done. 这件工作必须准确地按照她的要求做。