_____ of giant pandas is getting _____ because their living areas are becoming farmland.[ ]

A. The number, larger and larger      

B. A number, larger and larger

C. The number, smaller and smaller    

D. A number, smaller and smaller

DSA减影方式中，采用不同曝光能量进行图像采集，并进行减影处理的是（）

A.时间减影

B.能量减影

C.混合减影

D.光学减影

E.手动减影