There's like 18 knobs, you turn a knobup or down, and you're there. The outcome is pretty measurable.
温控系统大概有18个温控旋钮，你可以把一个旋钮调高或调低，结果都是很容易衡量的。
2
The experimenter is back there with the speed knob and at random intervals, he just speeds up the tape of their heart and then slows it down.
实验者带着速度旋钮回到那里，在随机的时间间隔里，他只是给他们的心跳录音带加速，然后再减速。
3
Each of the four fundamental forces (gravity, electromagnetism, and the strong and weak nuclear forces) has a kind of theoretical knob that can be turned up or down to change its strength.