X射线的穿透能力，与下列哪项无关（）X-rays' penetration ability is independent of which of the following（）

X射线的穿透能力，与下列哪项无关（）X-rays' penetration ability is independent of which of the following（）
A.物质的原子序数Atomic number of the material
B.物质的厚度Thickness of the material
C.射线的宽窄Width of X-ray beam
D.射线的能量Energy of X-rays
正确答案：射线的宽窄Width of X-ray beam