解释：在人活动范围内的水就污浊，在野外无人地方的水就清洁。同为一样的水，都是从天边开源，有的混浊有的清洁，这是它们所处环境使它们这样的。
The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'
There are no hard distinctions between what is real and what is unreal, nor between what is true and what is false. A thing is not necessarily either true or false; it can be both true and false.