网上看到的: We want to count all the books in the library. You count up shelf #1, I count up shelf #2. That's map. The more people we get, the faster it goes. 我们要数图书馆中的所有书.你数1号书架,我数2号书架.这就是“Map”.我们人越多,数书就更快. Now we get together and add our individual coun…