1·Each full battery charge provides approximately three hours of use.
冲饱电可以满足三四个小时的使用。
2·Most portable devices are often in need of recharging after just 2 to 4 hours of use.
大多数便携式设备往往需要充电后仅2至4小时的使用。
3·Over the course of 200 hours of use on two test units, lumen output degraded by 25% on both of them.
有两台测试样机在使用了200小时后，都降低了25%的流明输出。
4·Though the test unit with the high altitude fan engaged has diminished less over the first 100 hours of use, this was a much brighter unit to begin with.
虽然那台测试样机开启高海拔模式后使用100小时亮度削弱的更多，但那台也是所有样机中初始亮度更高的一台。
5·On one of our XJ-A130s, the max lumen output was 1228 when it was new. After 130 hours of use its maximum brightness dropped to 949 lumens, which is a 23% reduction.
我们手头的其中一台XJ-A130， 开箱时最大流明输出1228流明，但使用过130小时之后其最大流明输出降为949流明，降幅达23%。
6·Many people also don't use sunscreen properly—applying insufficient amounts, failing to reapply after a couple of hours and staying in the sun too long.
许多人也没有正确地使用防晒霜——涂抹的量不够，几个小时后没有重新涂抹，并且在阳光下待太长时间。
7·"Excessive Internet use should be defined not by the number of hours spent online but in terms of losses," said Maressa Orzack, a Harvard University professor.
哈佛大学教授马瑞莎·奥扎克说：“过度的互联网使用不应该用上网时长来定义，而应该用损失来定义。”
8·Our courses, totalling 20,000 hours of content in 20 different languages, guarantee you language skills you can use right away.
我们的课程总共囊括了二十种不同语言的内容，总时长达两万个小时，这保证你能学到可立即使用的语言技能。
9·Some other researches also show that children who use media at night go to bed later, get fewer hours of sleep each week, and become sleepy more easily during the daytime.
其他一些研究也表明，晚上使用社交媒体的孩子睡得更晚，每周睡眠时间更少，白天更容易犯困。
10·Why use story points instead of units of time such as hours?
为什么要使用描述点，而不是小时之类的时间单位？