白喉多由以下哪种病证所致（）
A.肾阴亏损，虚火上炎
B.肺胃热毒伤阴
C.湿热蕴毒上壅
D.肺胃气液两虚
E.疫毒上攻
参考答案：B
My brother can ______ very well. So he wants to join the ______club.[ ]
A. swims, swimming
B. swim, swimming
C. swimming, swim
请简述一台冷油器的退出操作。
