In fact,they found that at least 800 genes spring into action in a finch's brain whenever it sings.
VOA: standard.2010.04.05
If you put your fingers between the plastic opening at the bottom, and here's where you gotta watch out for the spring, pull the thing apart and that's it.
如果你把手指放到,底部的缝隙中间,这里你需要小心,你剥开就会发现这个了。
Newton is not going to come and tell you what force the spring will exert when it's pulled by some amount.
牛顿不会过来告诉你,弹簧被拉伸一定量时会产生多大的力
If you connect the body to a spring, which is neither compressed nor extended, there's no force acting on it.
如果将一个弹簧连在这个物体上,弹簧既没有被压缩也没有被拉伸,也不会有力作用在它上面
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