回答数
4
浏览数
205
blue-taste
how many books?
小白兔256
How many books?
shaaaronzy
设原来各有向本 (x-160)÷(x-420)=3 x=550 原来各有550本
水蓝冰蓝
many booksa lots of books希望帮助你
优质英语培训问答知识库