表语从句是跟在be动词之后的,比如:The reason of his abcence is that he met a traffic jam.
如果把你的这个句子变成:Is this the museum that they visited yesterday?这是个定语从句,先行词是museum.
表语从句是跟在be动词之后的,比如:The reason of his abcence is that he met a traffic jam.
如果把你的这个句子变成:Is this the museum that they visited yesterday?这是个定语从句,先行词是museum.