X线摄影时，想要降低人体的辐射剂量，可以采用（）When having a radiography, if you want to reduce the radiation dose of the human body, you can use（）

A.低能X射线Low energy X-rays

B.高能X射线High energy X-rays

C.长曝光时间long exposure time

D.短曝光时间Short exposure time

正确答案：高能X射线High energy X-rays