加an，因为它的发音是以元音开头的: /ɪkˈsperɪmənt/I decided to conduct an experiment.
我决定做一项实验。
The experiment went horribly wrong.
实验弄得一塌糊涂。
As an experiment， we bought Ted a watch.
作为尝试，我们给特德买了块手表。
This experiment was harmless to the animals.
这个实验对动物无害。
I've never cooked this before so it's an experiment.
我以前从未做过这种菜，所以这是一个尝试。
