"How often-your school sports meeting-?""Once a year."

正解是C .
根据时间状语how often 和答语 once a year 断定句子应该 一般现在时,另外句子主语是 物,your school sports meeting,故用一般现在时被动语态,其表达形式是 is held . 再问： 答案上的确是C 但是我想知道A错在哪里。
再答： A 用的是 does hold 是主动语态。 句子要是这么问就选A How often do you ( 主语是 人） ） hold your school sports meeting ? How often is＿your school sports meeting ( 主语是物) held ?