You cannot compete with those postgraduates.

你无法和那些研究生竞争。

Postgraduates are the essence of the society.

研究生是社会的精英阶层。

Postgraduates should not be allowed to cohabit.

研究生不应该允许同居。

Why? B:You can not compete with the postgraduates.

为什么?你可不如那些研究生有竞争力。

They provide a range of services for postgraduates.

他们为研究生提供一系列服务。