Regular repeating actions such as sound waves, light waves, or radio waves have a certain frequency, or number of waves per second.

有规律的重复活动如声波、光波、无线电波都有一个特定的频率，或者说是每秒的波动次数。

《柯林斯英汉双解大词典》

Another belief involving the number three has it that it is unlucky to light three cigarettes from the one match.

另一种与数字3有关的信仰认为，用一根火柴点燃三根香烟是不吉利的。

youdao

In Switzerland, if you were simply to anticipate a traffic light, the chances are that the motorist behind you would take your number and report you to the police.

在瑞士，如果你只是早于红绿灯行动，你后面的司机很可能会记下你的号码，然后向警察报案。

youdao

Does it need refinement in some way?" "And if it does need some adjustment in light of the events that have taken place over the last number of months, including the election and so on, and then what are the implications of that in terms of General McChrystal's resource request?" The secretary said the United States will not abandon its core mission in Afghanistan, which President Obama described as the destruction of the al-Qaida terrorist network, because it is "critical" to U.S.national security.

VOA: standard.2009.10.23

So this gives you a little bit of an idea of just how many individual photons there are in a laser beam of light. This is a huge number of photons.

这个给你们一点思路关于,一个激光束有多少独立的光子,这是一个巨大的光子数目。

麻省理工公开课 - 化学原理课程节选

So what we end up with for the number of photons in this laser beam of light is 2.1 times 10 to the 17 photons.

这个激光束的数目是,2，1乘以10的17次方。

麻省理工公开课 - 化学原理课程节选

The team also showed how a large number of light pipes could be used to form a kind of dot matrix display.

BBC: Disney develops 3D-printed lighting for toys

The board have ruled that Oakey's first defence must be against Brian Magee, the number one light heavyweight contender from Belfast, before the end of October.

BBC: Dominant Oakey crushes Spartacus

Patricia Hughes had many outside interests, including gardening, animals and the piano and she also wrote a number of light music pieces that the record producer Joe Meek helped her to have published - including one, It Happened in a Dream, which reportedly still earns royalties today.

BBC: Patricia Hughes