帧中继交换机的特性有()。
A.具有业务分级管理的功能
B.具有宽带管理功能
C.不具有用户线管理功能
D.不具有用户选用业务处理能力
E.具有网络同步能力
参考答案:A, B, E
下列各分子中,所有的原子都满足最外层为8电子结构的是 [ ]
A.BeCl2
B.PCl3
C.PCl5
D.N2
Mark Twain presented the 19th-century America in his own unique way. Discuss Twain’s art of fiction: the setting, the language, and the characters, etc., based on his novel Adventures of Huckleberry Finn.