In teaching you cannot see the fruit of a day's work. It is invisible and remains so, maybe for twenty years.

In teaching you cannot see the fruit of a day's work. It is invisible and remains so, maybe for twenty years.

在教学中，你不能看到一天工作的成果。它是看不见的，并保持这样，也许二十年。

-- Jacques Martin Barzun 雅克·马丁·巴赞