The visit to Damascus by U.S.envoy Mitchell is another step in what has been a cautious effort by the Obama administration to draw Syria into diplomatic engagement after years of strained relations.

VOA: standard.2009.06.09

It might not have any electrons in it, but it still exists, so you need to draw these into your molecular orbital diagram.

也许它里面没有电子，但它是存在的，所以你需要在分子轨道图里画出来。

麻省理工公开课 - 化学原理课程节选

It might not have any electrons in it, but it still exists, so you need to draw these into your molecular orbital diagram.

也许它里面没有电子，但它是存在的，所以你需要在分子轨道图里画出来。

麻省理工公开课 - 化学原理课程节选