治疗支原体肺炎，首选的抗菌药物为：（）
A.青霉素
B.磺胺类
C.红霉素
D.庆大霉素
E.链霉素
参考答案：C
— When did the computer crash?
— This morning, while I ________ the reading materials downloaded from some websites.[ ]
A. have sorted
B. was sorting
C. am sorting
D. had sorted
最常见的后纵隔肿瘤是()
A．畸胎瘤
B．胸腺瘤
C．胸主动脉瘤
D．神经源性肿瘤
E．淋巴源性肿瘤
