政治没有永恒的朋友,只有永恒的利益。
I’m not sure if I believe in God, but I believe in art.
大自然为所有活动都观察了合适的时间。
我们不能忽视煤炭的经济作用,但也不能忽视其环境影响。
I don't believe in heroes, but I believe in people who do heroic things.
The strength of a response tendency depends on the amount of reinforcement received.