A 69-year-old client asks the nurse what the difference is between osteoarthritis (OA) and rheumatoid arthritis (RA). Which response is correct

A. OA is a noninflammatory joint disease. RA is characterized by inflamed, swollen joints.
B. OA and RA are very similar. OA affects the smaller joints, and RA affects the larger, weight-bearing joints.
C. OA affects joints on both sides of the body. RA is usually unilateral.
D. OA is more common in women. RA is more common in men.

在采用高能射线进行射线照相时，不能在胶片暗盒背后放置铅屏蔽，因为（）

A、高能射线能在铅屏蔽上激发出较强的散射线

B、高能射线能在铅屏蔽上激发出较强的高能电子

C、使用铅屏蔽反而会降低影像质量

D、以上都对