It's useless to worry about things that already happened and cannot be changed.
I think I will buy the red car, or I will lease the blue one.
When something is incomprehensible due to complexity; unintelligble.
To greatly frustrate someone. To drive someone crazy, insane, bonkers, or bananas.
A task that's easy to accomplish, a thing lacking complexity.
To risk it all, even if it means losing everything. To go all out.
When something is about to begin, get serious, or put to the test.
Yeah, I think it's a good environment for learning English.