Vaccination is a life or death question for poor people and if you can vaccinate a child to prevent a disease from happening it is a lot more cost effective than it is to treat that disease afterwards."

VOA: special.2010.03.29

This is more well-established question of nurture, in terms of moving away from the way we normally teach to what is clearly more effective way.

这更是一种,培养方法问题，从我们平常的教学方法,转移到,明确的更有效的方法。

麻省理工公开课 - 媒体、教育、市场课程节选

They found that certain cells, in particular, epithelial cells from monkey kidneys, were very effective at propagating the virus.

他们发现有些细胞,尤其是在猴肾脏的上皮细胞中,这种病毒能够有效地增殖

耶鲁公开课 - 生物医学工程探索课程节选

And I think that kind of dysfunctional political system which was established has really deprived Georgia from effective governance.

VOA: standard.2009.09.01

So if we have total +2 and complete shielding -1 where that can actually negate a full positive charge, because remember our nucleus is plus 2, +1 one of the electrons is minus 1, so if it totally blocks it, all we would have left from the nucleus is an effective charge of plus 1.

抵消一个完全的正电荷,因为记住我们的原子核是,其中一个电子是,所以如果它完全挡住了它，我们从原子核中留下的，全部有效电荷就是，所以，在我们的第一个例子中,我们的第一种极端情况。

麻省理工公开课 - 化学原理课程节选

Campbell says it is in the interest of the United States and Mexico to prevent criminal gangs from gaining effective control of Juarez or any other parts of Mexico.

VOA: standard.2009.12.18

The electron completely canceled out 1 it's equivalent of charge from the nucleus, such that we only saw in a z effective of 1.

电子完全抵消了来自原子核的等量电荷,这样我们仅仅看到有效的z为，在极端案例b中。

麻省理工公开课 - 化学原理课程节选

The visa for James Elder, an Australian,has been canceled effective Monday, but officials say after an appeal from the United Nations he will be allowed to stay there under September 21.

VOA: standard.2009.09.06

And the point that I also want to make is the way that they differ, z effective actually differs from the total charge in the nucleus due to an idea called shielding.

我也想指出的一点是它们不同的方式,有效的z事实上不同于原子核的，总电荷量,因为屏蔽效应。

麻省理工公开课 - 化学原理课程节选

Some fire chiefs in California say that residents should always be encouraged to evacuate, but Naomi Brown, from the Australasian Fire and Emergency Service Authorities Council, says installing effective early warning systems is the key.

VOA: standard.2009.06.24