Charles Wortmann at the University of Nebraska-Lincoln says a one-time tillage may be used to correct a problem like aggressive weeds.

VOA: special.2010.09.28

Once each time. Right? I only do one swap potentially, it-- though not one potentially, each time at the end of the loop I do a swap.

每次循环做一次，对么？我其实,就可能做了一次交换，也许并不是可能，每次循环的结束我都得做一次交换。

麻省理工公开课 - 计算机科学及编程导论课程节选

About one-third of Southern white families at one time or another had at least a toehold in slave ownership.

大约三分之一的南方白人家庭,在某一段时期至少都拥有过奴隶

耶鲁公开课 - 美国内战与重建课程节选

But no - those surprised Russians thought that no one regiment by itself would come around there at such a time.

VOA: special.2011.03.26

At best, one could say Hobbes is a kind of part-time liberal at best.

为此，可能有人要说霍布斯至多,也就是个业余自由主义者。

耶鲁公开课 - 政治哲学导论课程节选

It's the old gray but dark philosophy that you should just look at value But, one of the things is when people have given up on a company--that's the perfect time.

就是那个陈旧黑暗的哲理,你应该只注重价值,但是，还有一种情况当人们都抛售了,某个公司的股票--那就是个极佳的时机。

耶鲁公开课 - 金融市场课程节选

People can get hung up on sort of hunting these things down, and stamping them out, one at a time. And it's a little bit like playing Whack-a-Mole. Right?

我们可能会一次一个的去发现,这个bug并且消灭它，这有点像打鼹鼠对不对？,不停的有鼹鼠跳起来？

麻省理工公开课 - 计算机科学及编程导论课程节选

You can only drive one car at a time and if you have five cars-- well I mean that's kind of-- all right you could have five cars and you could drive a different one everyday, but it's starting to seem a little ridiculous, right?

你只能一次开一辆车,而且如果你有五辆车,我的意思是那种...,好吧,你能有五辆车,而且你可以每天开不同的车,但是这有点荒谬,不是吗

耶鲁公开课 - 金融市场课程节选