以下哪些产品支持IPv6双栈()。
A.S5120EI
B.S7500E
C.S7500
D.S3600EI
E.S5500EI
F.S9500E
参考答案:B, E, F
以下关于三期梅毒损害的描述错误的是()
A.浅表性溃疡
B.容易损害肌和骨骼
C.心血管系统易受侵犯
D.孤立性浸润皮损
E.发生树胶肿
. — It seems you have been late for class more than once this week, Tom?
— My alarm clock ____ run because one of the parts is missing.
A.won’t
B.needn’t
C.mustn’t
D.wouldn’t