—What's the time now?

—It's _______ half past one. [ ]

A. much

B. about

C. many

D. at

慢性支气管炎急性发作患者，伴发热。使用头孢他定二周后，体温曾一度降至正常，症状缓解。后再次出现发热，经检查，口腔粘膜有白色念珠菌感染，此时抗生素拟改用

A．红霉素
B．氯霉素
C．青霉素
D．二性霉素B
E．环丙沙星