l haven‘t heard from tom recently,l know he is too busy____(write) 说明理由

问题描述:

l haven‘t heard from tom recently,l know he is too busy____(write) 说明理由

writing, be busy doing sth是固定短语,忙于做某事

writing
be busy doing sth=be busy with sth忙于做某事
祝你进步,有不会的可以再问我哦