Economists have long considered government spending, especially on infrastructure, to be an effective tool for revitalizing a stagnating economy.

VOA: standard.2009.10.16

But what you should be able to do is take a look at a list of answers for what we're saying z effective might be, and determining which ones are possible versus which ones are not possible.

但是你们应该能够做到的,是看一下这个可能的,有效电荷量的答案列表，并且确定哪些是可能的,哪些是不可能的。

麻省理工公开课 - 化学原理课程节选

where the super model could not be an effective model for bikinis after a certain age.

比基尼模特在达到一定的年龄后就无法再担任这份工作了。

退休很神奇 - SpeakingMax英语口语达人

So she says(In other words) while emergency contraception is effective for individual women, advance provision can't be expected to make a different in the community.

VOA: standard.2010.03.22

You just need to remember what's happening to z effective, which really tells us what's happening with all the trends, and once you know z effective, you can figure out, for example, what direction the atomic radius should be going into.

你只需要记住有效核电量的规律，实际上它会告诉我们所有的规律，只要你知道了有效核电量的规律，你就可以判断，比如，原子半径会向着哪个方向发展。

麻省理工公开课 - 化学原理课程节选

So our minimum that we're going to see is that the smallest we can have for a z effective 1 is going to be equal to 1.

所以我们能够看到的,最小的有效电荷量,等于。

麻省理工公开课 - 化学原理课程节选

So we should be able to calculate a z effective for any atom that we want to talk about, as long as we know what that ionization energy is.

我们应该可以计算出任何一个,我们想要谈论的原子的有效电荷量，只要我们知道电离能是多少。

麻省理工公开课 - 化学原理课程节选