n.精神失常;极蠢;
例句:
It's sheer lunacy driving in such weather.
天气这样糟糕还开车,真是疯了。
It's sheer lunacy driving in this weather.
天气这么坏还开车,简直是疯了.
What you're doing here is sheer lunacy.
你们在这做的事,干脆就是发疯.