often的用法?按所给词语的正确形式填空;he--（often）study at night是he often ——（

often 英音：['ɔ:fən] 美音：['ɔfən]
adv.（副词）
经常,再三
How often does the train run?
这火车多久一班?
【说明】此词一般用于动词之前,be 和助动词之后,有时也用于句末以加强语气.如:We often go there.We have often been there.We haven't been there very often.
习惯用语
as often as 每当
as often as not (=more often than not) 多次,屡次,往往
every so often 偶尔,有时
once too often 又一次,再一次,次数太多
often and often 屡次三番,经常
问：he often ——（study ）at night
答：He often studies at night