甲种水果每千克价格a元,乙种水果每千克价格b元,取甲种水果m千克,乙种水果n千克,混合后,平均每千克价格是______.
混合后,平均每千克价格是am+bnm+n.
元电荷所带的电荷量是( )
A.
B.
C.
D.
_____ coins is my hobby, because they are interesting. And I like them very much. [ ]
A. Collect
B. To collect
C. Collecting of
D. Collecting