1.All I know is that I'm going to be on the edge of my seat the whole game.
我确定，整场比赛我都会非常兴奋。
on the edge of one's seat:
(idiomatic) In suspense; waiting eagerly or anxiously for some resolution.
2.A lot of hard work has been going on behind the scenes.
舞台背后有很多不为人知的努力。
It was done behind the scenes.
这件事是暗中进行的。
behind the scenes:
(idiomatic) In secret; out of public view.
3.Hey, hope you break a leg tonight.
嘿，祝你今晚好运。
break a leg:
(idiomatic) Said to someone wishing they perform well in a theatrical production or comparable endeavor.
