可持续性不是一种选择；它是农业未来的必要条件。
Everyone is in favor of free speech. Hardly a day passes without its being extolled， but some people's idea of it is that they are free to say what they like， but if anyone else says anything back， that is an outrage.
钱不说话，它咒骂。
"My paintings are my children, each with its own soul."
我只知道我什么都不知道。
I'm the kind of person that has to learn the hard way.
蒸汽机中运动的产生总是伴随着一个我们应关注的情况，即热量的平衡重建。
The international system is inherently competitive, and states are constantly trying to outmaneuver each other.