These books mustn’t out of the reading room. You have to read them here. A. take B. be ta

问题补充：

These books mustn’t out of the reading room. You have to read them here.

A. take B. be taken C. be taking

答案：

解析：句意：这些书不能带出阅览室，你们必须在这里阅读。句子中主语books和谓语动词take是被动关系，故用被动式，其结构是系动词be+动词过去分词，故选B。