北京 vs 上海# WaterWorld - 未名水世界
k*o
1 楼
http://ngrams.googlelabs.com/graph?content=%E5%8C%97%E4%BA%AC%2C%E4%B8%8A%E6%B5%B7&year_start=1800&year_end=2008&corpus=11&smoothing=10
a graph of how often it was mentioned in a book (indexed by google)
throughout history.
a graph of how often it was mentioned in a book (indexed by google)
throughout history.