题目内容：

（ ）a year do you go swimming with your friend?
（ ）a year do you go swimming with your friend?
-----Once a month
A How often B How long C How soon D How many times
请选择并说明理由.

优质解答

选A 因为我们看回答是 once a month 是频率,提问频率的特殊疑问词是 how often
how long 是提问多长时间,如 for +时间段和since +时间点
how soon多久之后,提问in +时间段
how many times提问次数,如three times