"Perhaps most important,though, we can now field initial elements of the system to protect our forces in Europe and our allies roughly six to seven years earlier than the previous plan a fact made more relevant by continued delaysin the Czech and Polish ratification processes that have caused repeated slips in the timeline,".

VOA: standard.2009.09.17

Here is an example that shows some very, very metallic elements, groups one and two, and some non-metallic elements over here, five, six and seven.

举个例子,这个例子表明金属元素，第一族和第二族，与一些非金属元素,在这里，第五族，第六族，和第七族。

麻省理工公开课 - 固态化学导论课程节选