If the president decides to go with the higher troop levels recommended by the military, he will get support from congressional Republicans.

VOA: standard.2009.10.09

And as you go to higher and higher levels, those energy levels, as you saw in the case of hydrogen, are more closely spaced.

当能级变得越来越高，那些高能级的轨道，就会变得越来越接近，正像你在氢原子里看到的那样。

麻省理工公开课 - 固态化学导论课程节选