原式=4 26×8 12÷2 16
=2 23×2 32÷2 16
=22
=4．
小红买了15本练习本，共付了6元钱，每本练习本多少钱？（用方程解）
— I'm sorry for breaking your pen.
— Never mind. I have _____ one.[ ]
A. another
B. other
C. others
