有机化学的存在所以必要，还因为碳的化合物或混合物在我们日常生活中非常重要。

The existence of organic chemistry is further justified by the importance of carbon compounds or mixtures in our lives.

youdao

另一种说法是这种碳元素来自于火山，但这不可能，因为碳数量激增期比火山活动期要短得多。

The alternative, that the carbon came from the volcanoes, is unlikely because the spike is much shorter than the period of volcanic activity.

youdao

无论条件多么艰难，如果我们一起努力，也许有一天这个问题可以得以解决，因为碳排放是世界的焦点。

No matter how hard the condition will be, I think if we try our best together. Maybe the problem can be solving someday, because carbon emission is a focus of the world.

youdao

And because, of course, we have this carbon here what you end up doing is adding a carbon to your molecule.

因为，当然，我们这里有一个碳,接下来需要做的就是在你的分子中再加上一个碳。

麻省理工公开课 - 化学原理课程节选

So in terms of the first step of skeletal structure, this is actually going to be easier because we don't have a central atom, we just have carbon and nitrogen here.

对于第一步画出骨架，其实比刚才更容易,因为我们没有一个中心原子，我们这里只有碳和氮两个原子。

麻省理工公开课 - 化学原理课程节选

We have carbon 12. I will even leave off the 6 because we already know it is carbon.

我们有碳12，我们将6省去6,因为我们已经知道它是碳了。

麻省理工公开课 - 固态化学导论课程节选