And when we're talking about the amplitude of the wave, we're talking about the deviation from that average level. So, if we define the average level as zero, you can have either a positive amplitude or a negative amplitude.

当我们讨论一个波的振幅时,我们说的是偏离平均位置的量,如果我们把平均位置,定义为零的话，那幅值不是,正的就是负的，有时候人们在。

麻省理工公开课 - 化学原理课程节选

We could say an energy level diagram 0 This would be energy. Here is zero.

我们可以画一个能量图,这是能量，这里是。

麻省理工公开课 - 固态化学导论课程节选

The disease model,the optimum level is the zero: let's just be Ok; let's just not hurt.

对疾病模型而言，最优水平是零：,我们都平平安安，别受伤就好了。

哈佛公开课 - 幸福课课程节选

When it was suggested to Mr Prescott that not only was the zero level essential, but also that Sellafield was inevitably under threat, he said discussions had a long way to go.

BBC: News | UK | Sellafield to stay open - Prescott

Specifically, I had hoped that the anticipated addition of the Fed Funds targets of individual FOMC members which I thought was a bad idea would at least weaken their previous collective commitment to keep that rate at its near-zero level at least until mid-2013 which I also thought was a bad idea.

FORBES: The FOMC's Recent Transparency Moves: Worse Than Expected

You can't reduce them to a zero level, but we can try to reduce it as much as we can and I believe the rail industry is continually looking at this together with the regulators and the Health and Safety Executive to reduce it to as low a level as possible.

BBC: Rail firm defends safety record