"They do not represent official positions or policy, and they do not,in my view, fundamentally call into question the efficacy of our current strategy in Afghanistan and its prospects for success."

VOA: standard.2010.07.30

If you are trying to model, I don't know, the efficacy of a particular drug, these are the baby-steps that you will go through.

是否你正在试图创建模型，我不知道，一种特殊药品的功效，你们要经过一些入门步骤。

麻省理工公开课 - 固态化学导论课程节选

Which of us would want to punish the purest efficacy of a living intellect?

谁愿意批评,最纯洁的活跃的思想的成果？

耶鲁公开课 - 弥尔顿课程节选

He disputed the efficacy of some of the drugs, which is in a way just as bad or even worse - because it prevented access to drugs, which could have been affordable at least to South Africa, In the end, the words of Nelson Mandela became a battle cry for many at the Conference.

VOA: standard.2010.05.17