治疗肺炎链球菌肺炎首选
A．青霉素
B．红霉素
C．氯霉素
D．卡那霉素
E．庆大霉素
参考答案：A
解析：A【解析】治疗肺炎球菌肺炎的首选药物是青霉素。
They have tried, but _____ have passed the exam. [ ]
A. a few
B. few
C. a little
D. little
Zero-profit-point 零利润点
