Who's to say we would not have succeeded if we'd had more time?

要是时间更充裕，没准儿我们就已成功了，谁说得准呢？

《牛津词典》

Please do not hesitate to contact me if you have any queries.

如果有疑问就请尽管和我联系。

《牛津词典》

Are you pressed for time? If not, I suggest we have lunch.

你时间紧吗？如果不紧的话，我建议我们一起吃午饭。

《柯林斯英汉双解大词典》

African countries frequently have to wait for years, if not decades,for new medical products to trickle into their health systems.

VOA: special.2011.01.19

So, that's a homogeneous system, one phase. You have to know if your system is an equilibrium system or not.

所以这是个均匀系统，只有一个相，你得知道你的系统,是不是个平衡系统。

麻省理工公开课 - 热力学与动力学课程节选

but if you explain it to your friend that you or she should not have or should have done something,

如果你想要向你的朋友解释，或者她应该做某事的时候，

I should have 课堂 - SpeakingMax英语口语达人

He said the management buyout - backed by an investor syndicate - would not have gone ahead if they did not have faith in the business.

BBC: Border Precision Engineering owners voice job optimism

If not, Have Your Say could turn into "Have Your P45" for whoever gave this the go-ahead...

BBC: NEWS | UK | Magazine | From the editor's desktop

What is the point, after all, of making these various noises if not to have an effect on a listener?

WSJ: Listen to Your Listeners | Postmodern Times by Eric Felten