Translation of "Grasp" in Chinese

He has a good grasp of English.

他精通英文。

She has a thorough grasp of her work.

她对她的工作十分在行。

One needs to buy a house that's within one's means, but one also needs to grasp an opportunity.

买房要量力而行，但也要把握时机。

I never know what to say to people who have absolutely no grasp of the basic facts and are too ignorant to realise it.

对于那些连基本事实都搞不清楚而且又盲目得无法了解到这一点的人，我从来都不知道对他们说些什么。