可用抗毒素进行紧急预防与治疗的疾病是（）
A.结核
B.破伤风
C.伤寒
D.百日咳
E.菌痢
参考答案：B
He pretended to be French, but his German accent _______.
A．gave him up
B．gave him off
C．gave him out
D．gave him away
在粗缆以太网中，如果使用了中继器，那么粗缆缆段最大长度不超过 【6】 。
