治疗肺炎杆菌肺炎首选的抗生素是（）。
A.氨基苷类抗生素
B.青霉素
C.头孢唑啉
D.氧哌嗪青霉素
E.红霉素
参考答案：A
Although we all know it is good to do international trade between countries，we still have to face some risks while doing international trade．Such risks mainly include economic risks and( )．
A．non-acceptance
B．foreign exchange rate
C．currency
D．political risks
类风湿关节炎下列哪项表示本病的活动（）。
A.类风湿结节
B.晨僵
C.关节畸形
D.关节疼痛
E.关节功能障碍
