The Bei sentence can be used to express passive voice. The structure is subject + 被 + object + verb + other elements. The subject is the patient of the action, and the object is the agent. If there are any negative adverbs or modal verbs, they should precede Bei.Examples:我被男朋友影响了。I + bei + boyfriend + influenced= my boyfriend influenced me我的照相机被谁拿走了?My camera + bei + who + took= who took my camera?问题还没有被解决呢。Problem + not yet + solved= the problem hasn't been solved yet