two-accelerator effect

The contraceptive effect wears off in two days.

避孕效果两天就会消失。

《柯林斯高阶英汉双解学习词典》

Psychologists have shown that babies apparently expect their world to comply with the laws of physics and cause and effect as early as two months of age.

心理学家们已经表明，早在2个月大时，婴儿就似乎期望周围的世界符合物理定律以及因果关系。

四级真题- 2018年 12月 3卷 阅读A

The law has had little measurable effect since it was introduced two years ago.

这条法规自两年前推行以来收效甚微。

朗文当代高级英语词典 第6版

The caffeine, the equivalent of two strong cups of coffee, was sufficient to reverse this effect, with some cyclists even displaying increased eye movement speeds.

溶剂中的咖啡因相当于两杯浓咖啡，足以扭转这一影响，有的自行车手眼动速度甚至加快了。

四级真题- 2017年 6月 2卷 短文填空

The two expressions are, in effect, identical.

这两种说法实际上一模一样。

外研社英语同义词辨析词典