ought to

ought to
应该
China ought to make a greater contribution to humanity.
中国应当对于人类有较大的贡献。
He is a very good tennis player; you ought to see him in action.
他是个很好的网球运动员，你应当去看看他打球。
I think there's a train at 8.20 but you ought to make certain.
我想8点20分有一班火车，不过你应该打听清楚。
I think you ought to go to/to go and see the doctor.
我认为你应当去找医生看看病。
You ought to scrap the old bike and buy a new one.
你应该扔掉这辆旧自行车，买一辆新的。
You ought to have a haircut.
你该去剪发了。

详解：

ought to 和should这两个情态动词均可表示“应该、应当”之意。
ought to:侧重反映客观情况，多在涉及法律、道义、责任、义务或原则时使用。
should:侧重自己的主观看法，语气比ought to稍弱一些。

or else<-->out of breath