Pandemic experts explain a second wave does not necessarily entail any change in the composition of the virus.

VOA: standard.2009.09.04

So, if something cycles through five wavelengths in a single second, we would just say that the frequency of that wave is five per second.

如果一个东西在一秒,内经历了五个波长，我们就说这个波的,频率是每秒5次。

麻省理工公开课 - 化学原理课程节选

The second I walked in, a wave hit me,

我进去的那一瞬就感受到了一股热浪，

哥伦比亚的氛围 - SpeakingMax英语口语达人

An estimated 30,000 people marched through Athens Thursday in a second wave of protests against civil service pay cuts and a freeze on pensions worth $6.5 billion.

VOA: standard.2010.03.11

The second thing is, just as in the case of the violin string, the wave equation, as posed by Schrodinger, has a plurality of solutions.

第二，就那个小提琴弦而言，波动方程，被薛定谔所提出的，有许多解法。

麻省理工公开课 - 固态化学导论课程节选

Senior Red Cross Officer for Health in Emergencies,Tammam Aloudat, says countries in the Northern hemisphere have gone through the first wave of the Swine flu pandemic and now have to prepare for a second wave of the virus.

VOA: standard.2009.09.04

The second, the abolition of the family, and the third wave being the establishment of the philosopher kings.

第二波，不要家庭；,第三波,设立哲学家国王。

耶鲁公开课 - 政治哲学导论课程节选

Similarly, with the second hydrogen atom, we've got the nucleus in the middle, and the 1 s b wave function around it.

类似的，在第二个氢原子里面，我们在中间有原子核，周围有1sb波函数。

麻省理工公开课 - 化学原理课程节选

And when we describe this in terms of talking about chemistry terminology, we would call the first one the 1 s, and 1 is in parentheses because we're talking about the first electron there, and we would multiply it by the wave function for the second one, which is also 1 s, but now we are talking about that second electron.

当我们用化学术语来,描述它的时候，我们称第一个为“1s“,括号中的1是因为我们,在谈论第一个电子,而且我们会用它的波函数，乘以第二个,第二个也是“1s“,但是我们现在谈论的是,第二个电子。

麻省理工公开课 - 化学原理课程节选