用显微镜进行观察时，放大倍数最大的镜头组合是（ ）
A：目镜5X，物镜10X
B：目镜5X，物镜40X
C：目镜10X，物镜10X
D：目镜20X，物镜40X
Mike bought an old car cheaply，cleaned it up and sold it at a ______．
