试管婴儿的研究是出于帮助不孕夫妇的愿望。

Leadership is about making tough decisions today that will benefit generations tomorrow.

To write is to breathe, to live, to exist.

释义：善于用兵的人，会顺应天地的规律，与之同行。这句话强调用兵之道在于顺应自然。