物体厚度越大，X射线的穿透本领越　。（请填写大或者小）The greater the thickness of the object, the　the X-ray　penetration power.（Please fill in larger or smaller)

物体厚度越大，X射线的穿透本领越　。（请填写大或者小）The greater the thickness of the object, the　the X-ray　penetration power.（Please fill in larger or smaller)
正确答案：小