They're painkillers. You take one tablet when you feel pain, but not more than once with four hours.

那是止痛药。疼时吃一片，四小时后才能服第二次。

youdao

The development team estimated ten defects per week during the two weeks after a new release was deployed, and three defects per week otherwise, with four hours for analysis.

开发团队估计在部署新版本之后的两周内，每周会出现10个缺陷，如果进行过4小时的分析，则每周出现3个缺陷。

youdao

We heard about a special intensive reading program that required students to spend four hours every day in a small room with an instructor.

我们听说了一个特殊的精读项目，要求学生每天在一个小房间里和老师呆上四个小时。

youdao

They came out four hours later after talks with the president and other officials.

VOA: special.2010.06.19

One is called the twenty-four hour recall and that's either done by a computer, or done by a trained interviewer who would sit down with you and say, 'Let's reconstruct everything you've eaten in the last twenty-four hours.' And so then you have to recollect everything you ate in the last twenty-four hours.

其中之一被称为24小时回顾法,可由计算机完成,也可以由专业测试人员,坐在你面前并对你说,"让我们记录所有,最近24小时你所吃的东西",然后你需要回忆,最近24小时内吃了什么

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

"Three or four hours before I could fall asleep. I wake up three o'clock in the morning with the same stuff on my mind, tossing and turning.

VOA: standard.2010.05.04

Bursting with nearly four hours of sensational behind-the-scenes footage, cast and crew interviews and more, the Transformers: Dark of the Moon Blu-ray 3D, Blu-ray and DVD combo pack delivers blockbuster entertainment.

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With high usage, four hours is not particularly acceptable and surprising with a smaller display size than other larger tablets, although there is actually only a marginal difference in current drain between a smaller and larger display.

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Last week I was with him for four hours listening to stacks of old 78s.

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