过去总是紧张的,未来是完美的。
能源转型不会一夜发生,但我们必须现在就开始。
Language is not just a system of symbols, but a set of practices with social and cultural significance.
酸和碱是互补的;没有另一个,一个就无法存在。
The blood in the animal body is impelled in a circle, and is in a state of ceaseless motion.