Shanghai Metro, China. The 468km network of the Shanghai Metro makes it the world's second longest. Shanghai Metro is the third rapid transit system in Mainland China, after Beijing and Tianjin. Shanghai Shentong Metro operates the network through its four subdivisions.
fermentation. n. 1. (Biochemistry) a chemical reaction in which a ferment causes an organic molecule to split into simpler substances, esp the anaerobic conversion of sugar to ethyl alcohol by yeast. Also called: ferment.
Yeast is actually a living microorganism, a fungus, that converts  fermentable sugars in the bread dough into (among other things)  carbon dioxide. The CO2 inflates the doâ¦ugh; the yeast makes  countless tiny bubbles of the gas. This is the mechanism behind the  dough rising.