The official number is secret, but news reports say the general wants about The request is controversial, not least because with the U.S.troop level in Iraq expected to remain around its current 120,000 for at least several more months, the strain on the U.S.Army is considerable.

VOA: standard.2009.10.13

So, we have a problem here if we're thinking about keeping things at the lowest energy, so there's a lot of ring strain in the system.

现在有个问题,我们考虑要把能量降到最低，所以环上有许多应力。

麻省理工公开课 - 化学原理课程节选

So, we have a problem here if we're thinking about keeping things at the lowest energy, so there's a lot of ring strain in the system.

现在有个问题,我们考虑要把能量降到最低，所以环上有许多应力。

麻省理工公开课 - 化学原理课程节选