all前面用an。
all前面用an,一般发音是元音字母的话，用an。
But it wasn't all an act, was it?
但不全是演戏，对吧？
Just kind of figured he'd give us all an oral history in alien-interrogation techniques.
我原以为，他会给我们讲讲外星人是如何审问他的。
and it's all an experiment, and it's all voluntary.
这一切都只是个实验，都是自愿的。
Everything negative--pressure, challenges--is all an opportunity for me to rise.
压力、挑战，这一切消极的东西都是我进步的机会。
All an observer can do on the ground is say, this is what we've seen.
在现场的观察员所做的事情只有说明他们所看到的事情。
