粮店运来16袋大米,每袋30千克,运来大米的重量比运来面粉重量的2倍少80千克,运来多少千克面粉?
It wasn't easy having my friends talk about their freshman years____ I wasn't a part of.
往无色溶液中滴加氯化钡溶液产生不溶于稀硝酸的白色沉淀,则无色溶液中( )