I think that life is a gift and that it is important to take advantage of every moment.

对黑洞的研究彻底改变了我们对空间和时间的理解。

I don't really think about age. I think people are as old as they feel and act.

【讲解】：（教学生）不到他苦思冥想怎么也弄不明白的时候，不去开导他；不到他想说而又说不出来的时候，不去启发他。告诉他（四方形）的一个角，他不能由此推出另外三个角，就不再往下教他（新知识）了。