Involvement in sports, in particular, rose almost 50% from 1981 to 1997: boys now spend an average of four hours a week playing sports; girls log half that time.

特别体育运动参与率从1981年到1997年上升了近50%：男孩们现在平均每周花四个小时做运动；而女生则只花一半的时间。

youdao

In one such case, a 50% increase in productivity was observed across a team of 25 analysts using a new SA; in another, the time taken to complete a task was reduced from 2.5 hours to four minutes!

在一个这样的案例中，25位分析人员组成的团队在使用一个新的SA时观察到了50%的工作效率提高；在另一个案例中，完成一项任务所花的时间从2.5小时减少到了四分钟！

youdao

The time of interrogation and investigation shall not exceed twenty-four hours in complicated cases subject to detainment according to these Regulations.

对情况复杂，依照本条例规定适用拘留处罚的，讯问查证的时间不得超过二十四小时。

youdao

A new study found better results in four-year-olds who go to bed around the same time every night and sleep at least eleven hours.

VOA: special.2010.06.09

Americans spend the most time out of any other people in the world volunteering in average four hours a week, volunteering outside their job which may also have a social objective more than any other people in the world.

比其他任何人所花的时间都多,平均每周有四个小时做志愿者的工作，做与自身工作无关的善事,他们比世界上其他人更具社会目标。

哈佛公开课 - 幸福课课程节选

"Now we have what we would call rush hour conditions or peak travel conditions for as much as eight hours during the day - about three to four hours in the morning and similar time in the evening."

VOA: standard.2010.07.26

The Toshiba has 128 GB of storage, and in my laptop battery test, it turned in a mediocre time of four hours and two minutes, which likely would approach five hours in normal use.

WSJ: The Convertible PCs

For the first time in four hours, there was no shooting.

NEWYORKER: The Taliban��s Opium War

The fans are certainly buying in: they filled the Coliseum with its first opening night sellout in four years, many arriving three hours before game time to tailgate in the parking lot and partake in outdoor festivities that included a live band along with assorted games and contests.

FORBES: Their Next Home Uncertain, the Islanders Press On