I'd give anything if he'd say 'I love you,' but it's just not in his nature.

如果他说声‘我爱你’，我愿意付出一切，可这根本不是他的性格。

youdao

If you have the right genes and are selfless, optimistic and active but still find yourself down in the dumps, just give it some time.

如果你有好的基因还很无私、乐观、好动，但依然觉得自己情绪萎靡不振，那就让时间来说明问题吧。

youdao

All the hard work in the world can't change those initial factors, which is not to say you should just give up if you were born poor.

所有的努力都不能改变这些既定的因素，但这并不意味着你出生在穷人家就应该放弃努力。

youdao

These won't be graded, you don't have to turn them in, it's just to give you some extra practice if you want while you're studying for the exam.

这些题目不会记分，你们也不需要交上来，只是如果你需要的话，这可以让你,在准备考试的过程中得到更多的训练。

麻省理工公开课 - 化学原理课程节选