The heart is not a metaphor.
心不是一个隐喻。
I don't sing because I'm happy; I'm happy because I sing.
"In science, the credit goes to the man who convinces the world, not to the man to whom the idea first occurs."
"The world is full of small things that are big enough to break your heart."
农业成功的真正标准不仅是产量，还有生产它的生态系统的健康。