要给儿童提供一个使他们得到满足的环境，必须努力了解儿童的需要。

I was in the middle before I knew that I had begun.

我们不能把问题留给下一代解决，我们现在就必须尽自己的一份力。

The value of a network is proportional to the square of the number of connected users of the system.

巨大的痛苦是无声的。