The only limit is the one you set yourself.
如果你是用信用卡租车,不要购买额外的保险。
"Model checking is a powerful technique for verifying the correctness of finite-state concurrent systems."
若我遇你,经年之后,我该如何贺你,以眼泪,以沉默。
对你帮助最大的书是那些让你思考最多的书。
I've wanted one thing for my whole life - to be happy.