But Michael O'Donnell says the number of serious bird strike incidents has remained at or below two hundred each year.

VOA: special.2009.04.01

I once counted the number of times he used the word the letter--O--in that poem, and I quit counting.

我曾经数过他到底在诗里用了多少个"啊",最后我放弃了

耶鲁公开课 - 美国内战与重建课程节选

You can actually say big O of 1, big O of 1 being constant time, the same number of steps.

其复杂度为O，表示时间是一个常量，所用的步数是相同的。

哈佛公开课 - 计算机科学课程节选

The people who started the company named it Google because in mathematics, googol,spelled g-o-o-g-o-l, is an extremely large number.

VOA: special.2009.04.19

"There are concerns in most O.E.C.D.countries that the number of nurses is too small to respond to the demand.

VOA: special.2010.06.07

At current growth rates, the W.H.O.expects the number to reach twenty million by two thousand fifteen.

VOA: special.2009.07.15

The W.H.O.says insecticide-treated bed nets have been shown to reduce the number of malaria cases by fifty percent and the infection rate by ninety percent.

VOA: special.2010.04.20