I can't finish this part of the puzzle.とは 意味・読み方・使い方

I've tried hard to solve this puzzle but I can't. I give up.

I cannot decide this matter.

This razor won't cut.

I can not deal with this hard problem.

At this rate my homework will never be finished.

I won't pass this bad piece of work.

Do what I will,

Try ever so hard,

To do my utmost,

I can not solve this problem.

This stain will not come out.

I cannot put this into practice until that is finished.

Such being the case,

I can not leave off.

We cannot afford to leave the negotiations deadlocked.

I cannot draw that conclusion.

Now is the time, or never

Now or never!

We cannot allow the matter to get any more complicated [involved].

This problem can hardly be dismissed as unimportant.

I cannot be satisfied with this sort of toy.

I'm sorry I couldn't finish it.

The difficulty is not to be overcome

The difficulty is insurmountable.

It is impossible to break through this hopeless situation.

I can't go this arrangement.

Now is the time, or never

Now or never!

Concerning this matter, I cannot compromise any further than this.

I will not give an inch on this point.