"Our margins are really thin, in terms of our bottom line, and any additional costs have to be absorbed by the farmer because we can't pass on those costs to consumers directly,"

VOA: standard.2009.12.12

Of course, we have to also know how to plug in the numbers so we can pass all the tests, but it's good to understand the nature of the edifice set up by Newton.

当然,我们首先要知道怎么代数字,这样我们考试才能过关,但是如果能理解,牛顿的这一伟大杰作的本质就更好了

耶鲁公开课 - 基础物理课程节选