―Excuse me, Jim. Do you have any books about Chinese history?

―Yes. ______ book above the shelf is _______ useful one.

A．The, a

B．A, the

C．The, an

D．An, the

患者，男性，28岁，双膝关节及踝关节红肿痛热1周，发病前3周有腹泻病史。RF阴性，受累关节X线无明显改变，最可能的诊断()

A．风湿性关节炎

B．类风湿关节炎

C．感染性关节炎

D．骨关节炎

E．反应性关节炎