单选题 8.  Mt. Bishop High School ______ as the town's emergency center, mainly because its buildings are reinforced with steel.
【正确答案】 C
【答案解析】 选项A错误,主语是school,谓语动词应该用第三人称单数。选项B错误,使用一般过去时表示学校做过选择,句意不通。选项C正确,此处使用一般过去时的被动语态。选项D错误,这是过去完成时的主动语态。