The strength of a response tendency depends on the amount of reinforcement received.
我们对明天认识的唯一限制是我们今天的怀疑。
书籍的魔力在于它们可以带你去任何地方。
I’m not perfect, and I don’t pretend to be.
The sustainable development of the coal industry requires the coordinated efforts of policy, technology, and the market.