Seeing is believing. 眼见为实。

count on “依靠，指望”
bank on “指望，信赖

Either way. 怎么都行

Whatever. 什么都行。

Up to you. 随便你吧。

rest assured“放心”

A piece of cake. 小菜一碟

a hundred percent“百分之百，完全”

beyond one’s ability “在某人能力范围之外

monkey in the middle 两头受气的人，两边不讨好的人
Every time when my wife and my mom have an argument, I'm the monkey in the middle

“show off”的意思是“卖弄，炫耀”，

例如：Don't take any notice of him; he's just showing off.
She always shows off her knowledge of literature.

“in the bag”“十拿九稳的，稳操胜券的”，可以理解为“已是囊中之物”，例如：We've got the match in the bag.

make up one’s mind“下决心，拿定主意

我知道，犹豫者终难成事。I know that he who hesitates is lost