do or die

基本解释

Now we are going back to that critical moment: is it do or die (well, the sun will come up tomorrow morning anyway)?
现在我们要回到最关键的问题：是做还是死（当然，无论如何在第2天早晨太阳还是会照样升起的）?
Uberman, being more severe and more extreme, becomes habit a lot quicker once you get the hang of it; and you get the hang of it faster, because it's more "do or die" for your body.
Uberman计划更严格更极端，但你能更快掌握它的窍门，因为它对你的身体更极端：要么坚持下去，要么别想学会。
When you approach the idea of networking as a 'do or die' situation, you're going to get nothing (especially valuable contacts) out of it.
当你处于ꂽ“决一死战”的社交情形时，你从中什么也得不到（特别是有价值的信息）。

They say many people die or are injured by the gas because they do not use these devices correctly.
Now, having said that, of course, that doesn't in any way mean that it's a good thing that we die when we do at 50 or 80 or 100.
说明这个观点后，当然那并不意味着,我们在50，80，100岁时死掉,是件幸事。
耶鲁公开课 - 死亡课程节选
You might ask though,is there some other behavior, something else that should tip us off,could tip us off, as to whether or not we really do or don't believe that we're going to die?
你可能会问，有没有其他行为，能够让我们突然醒悟，知道我们真正是否相信自己会死呢？
耶鲁公开课 - 死亡课程节选

Mr. NOWICKI: Well, I think if - New Hampshire is really do or die for McCain.
NPR: McCain Keeps Home Fires Burning

said when you are in a situation in which you must take a big risk in order to avoid failure