平行结构：由并列连词连接的A与B都应该使用用样的结构词、短语、句子,也就是说A是名词,则B也是名词；A是句子,B也是句子.
常见的连词：
both A and B
either A or B
neither A nor B
not only A but also B
Both my mother and my father are teachers.(名词）
You can either stay here or leave.（动词）
Not only does he like reading but also he likes writing.（句子）