And that's terrifying, because the theoretical models that always work out in the answer key in the back of a teacher's edition, that's great, but it's scary to talk about sources of error when the theoretical does not match up with the practical.
这很有意思，对吧。 因为理论模型总是得出 和教师版后面的答案一样的答案， 这很好， 但谈到错误的来源， 当理论不符合实际的时候，就让人害怕。