"There are concerns in most O.E.C.D.countries that the number of nurses is too small to respond to the demand.

VOA : special.2010.06.07

And the last example that we're going to talk about is thionyl chloride, so it's s o c l 2. This is another good step forward, because now we actually have four different atoms in our molecule.

我们要讨论的最后一个例子,是氯化亚砜，就是硫，氧，氯，二，这又是一个进步，因为我们的分子中现在有四个不同的原子了。

化学原理课程节选 : 麻省理工公开课

So I show that here, so in green, you have what's called a carboxcylic acid group, a c o o h, which gets converted by s o c l 2 to a c double bond o c l or an acid chloride.

我在这里用绿色表示，我们所说的羧酸族化合物，碳，氧，氧，氢，它被亚硫酰氯转化为,一个碳氧双键与碳氯单键组成的酰氯。

化学原理课程节选 : 麻省理工公开课

The only evidence was cut into a tree and a fence: the letters C-R-O and the word Croatoan,C-R-O-A-T-O-A-N.

VOA : special.2009.08.17

"By two thousand and twenty, C.O.P.D.will likely be the third leading cause of death across the world."

VOA : special.2009.06.23