How many times, 强调次数。
how long 意思岁罩为多久。回答可能会铅雀歼为 15minitus a day
how often 也可以，但槐冲是应该去掉a day. How often do you feed your pet? Twice a day.
表示频率，用How many times
如果用How often ，应该空洞这样说：How often do you feed your pet?
how long 不能问频亩纤率。
【俊狼猎英】团队为斗耐枯您解答。
how many times a day do you feed your pet? 一厅缓天喂几次宠物
Twice a day 一行毁天两次
how often 多久 回答的是时间 是 时扮带模间 段
how long 多久
选how often
how long的意思是多久、棚尘多长世茄（时间），how many times的意思是多少链返禅次、第几次，how often的意思是多长时间一次