A: It's a worry to me whether he is able to pass the exam or not.我担心他是否能通过考试。
B: I think he is able to pass with your help.有你的帮助,我想他能通过的。
A: I'm not sure.我不敢肯定。
B: He's been working hard recently, hasn't he?他最近一直都很努力,不是吗?