Translation of "Superficial" in Chinese

He has only a superficial knowledge of Japanese.

他對日文只是略懂皮毛。

You have to acquire real skills, not just superficial knowledge.

你要學的是實實在在的技能，而不單是表面的知識。

One must have conviction in law, or its existence will be superficial only.

法律必须被信仰，否则形同虚设。

His essay gave only a superficial analysis of the problem, so it was a real surprise to him when he got the highest grade in the class.

他寫的文章只分析了問題的表面，所以他知道自己拿了全班最高分的時候，不禁感到十分驚訝。