正当理由

You HAs no grounds to agoing away of the contract.

你们么有正当理背弃合同。

The rights of citizens must not be abridged without proper cause.

没有正当理, 擅自剥夺公民的权利。

I think it is a totally unwarranted waste of public money.

我认为这是毫正当理地浪费公款。