how often does she visit her grandfather为什么要用howoften
问题描述：
how often does she visit her grandfather为什么要用howoften
答
how often 对频率提问,表示多久一次,所以用它.
how often does she visit her grandfather为什么要用howoften
how often 对频率提问,表示多久一次,所以用它.