灵验的英文：
efficaciousness
efficatious

an efficacious remedy
灵验的药物

This medicine is highly efficacious.
这药很灵验。

Does he ever prophesy right?
他的预言灵验吗?

This medicine is highly efficacious
这药很灵验。

Last year's divination had proved all too accurate
去年他们“卜”的非常灵验。

This mew medicine has worked wonders for my stomachache.
这种新药治我的胃痛很灵验。

But the "fateful" garlic proved to be not so psychic after all
然而那“命运”的大蒜头这次竟不灵验。

feeling of efficacy
效力感

The efficacy of the medicine is satisfactory.
这药的药效令人满意。

Saturation does not increase efficacy.
饱和剂并不增加疗效。

The efficacy of this intervention has not been determined conclusively.
这种干预的功效尚未最后确定。

Because it has the same efficacy as operative knife.
因为它能起到手术刀一样的效果。