The relationship between wages and employment is not as straightforward as some models suggest.

估计问题的性质与检验统计假设的问题不同。

Sometimes, the hardest battles are fought within the confines of our own minds.

Hope is a good thing, maybe the best of things, and no good thing ever dies.

文学不是用来解决问题的，它是用来呈现问题的。

解析：良知在未发之时即已存在。