First of all, it will only be a minute or two at a time, maybe once or twice a lecture.

首先，每次只有一两分钟，一堂课最多不超过两次。

哈佛公开课 - 幸福课课程节选

Yeah, I get homesick at least twice a quarter, I think.

想，我每个季度至少想家两次。

想吃中餐的时候 - SpeakingMax英语口语达人

Alright, I have the problem so clearly this algorithm whatever it's gonna be is gonna be at least twice as fast because I'm doing half as much work.

现在，这个问题已变得清晰,不管怎么样，排序算法的效率,至少是之前的两倍,因为我只需要做一半的工作。

哈佛公开课 - 计算机科学课程节选

If some group, let's say you have cholesterol of two hundred and your relative risk is established at one, and then if you have cholesterol two fifty your relative risk is two, that means you have twice the risk, so relative risk of two is twice the risk, three is three times the risk, etc.

比如说有一个组,胆固醇水平200,相对风险设为1,另一个组胆固醇水平是250,相对风险是2,即第二组的相对风险是参照组的两倍,相对风险是2代表两倍风险,3代表三倍风险,如此类推

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选