certain obligation

基本解释

A good citizen has certain obligation to society.
一个好公民对社会有某些义务。
The possessor of registered trademark is the one who owns the registered trademark right and undertakes certain obligation according to the law.
注册商标所有人是指对其注册商标依法享有权利、承担一定义务的商标注册人。
If you are unhappy with a certain obligation or relationship you entered into some time ago, then decide whether you want to try to fix things or leave the deal or relationship altogether.
如果你对不久前开始的某个义务或关系感到不高兴的话，决定是要尝试去修补还是要把这些事情或关系全部放下吧。

Germany, the most biofuelled nation in Europe, has replaced a tax break with a straightforward legal obligation for refiners to blend a certain proportion of biofuels into their wares.
ECONOMIST: Can biofuels save Europe, or the planet?
Calls give you the right, but not the obligation, to buy shares at a certain price.
FORBES: Magazine Article
It is the right, but not the obligation, to buy something at a certain price.
FORBES: Consider Your Options