Don't let the cat out of bag. If our teacher knows this
she will punish us.
不要泄密，如果老师知道了这件事，她会惩罚我们的。
I'm afraid sooner or later, she will know it.
我恐怕迟早她会知道的。
If we keep the secret she will never know the truth.
只要我们保守秘密，她将永远不会知道真相。
I'll do my best.
我会尽力而为。
punish vt.惩罚，处罚
do one's best 竭力，尽全力