妊娠期淋病可用下列哪些药物治疗()
A．氧氟沙星
B．阿奇霉素
C．四环素
D．环丙沙星
参考答案：B
The happy student was singing _____ he was walking.[ ]
A. until
B. as
C. since
D. and
最佳比燃耗 optimum specific burnup
