And it's a pool that's too difficult to fully characterize, even by modern methods, and the product looks brown, like this tar here on the left. A pure compound is shown on the right, for contrast.
很难分类区别这一堆东西 即使是用现代技术 产生物就像左边这个焦油一样棕色的 而纯化合物 则是右边用于对照的这样