OK, elements with low average valence electron energy, and here I'm saying below 11 electron volts, these are good electron donors.

平均价电子能都较低的元素，我是指那些低于11电子伏的，这些是很好的电子给体。

麻省理工公开课 - 固态化学导论课程节选

Over here in the lower left corner, we have elements that as a group have very low values of average valence electron energy.

在底层的左侧角落，我们看到以组为单位的,价电子能较低的元素。

麻省理工公开课 - 固态化学导论课程节选

The average speaker knows, as a low-ball estimate, about 60,000 words.

保守估计,说话者平均知道大约六万个词

耶鲁公开课 - 心理学导论课程节选

So, for example, we have this average level, and then it can go high where we have the peak, or it can go very low. We can also discuss sound waves, so again it's just the periodic variation of some property -- in this case we're talking about density, so we have high density areas and low density areas.

例如这是平均位置，在峰的位置水位高，在谷水位低，我们也可以,讨论声波它也是某种,量的周期变化，在这里我们,讨论的是密度,我们有高密度区和低密度区。

麻省理工公开课 - 化学原理课程节选

It's got a very low average valence electron energy.

它的平均价电子能很低。

麻省理工公开课 - 固态化学导论课程节选

These have low average valence electron energies.

他们有较低的平均价电子能。

麻省理工公开课 - 固态化学导论课程节选