11．RS—232標(biāo)準(zhǔn)接口電路采用

A．同步方式                                                        B．開(kāi)放型

C．平衡型                                                           D．非平衡型

12．400MHz電波信號(hào)屬

A．微波                                                               B．長(zhǎng)波

C．中波                                                               D．短波

13．用數(shù)字量多路開(kāi)關(guān)SN74150采集遙信信號(hào)時(shí)，欲使W=E14，數(shù)據(jù)選擇端ABCD應(yīng)為

A．0111                                                               B．1110

C．1101                                                               D．1011

14．(15，7)循環(huán)碼的全部許用碼組有

A．256個(gè)                                                            B．129個(gè)

C．127個(gè)                                                            D．128個(gè)

15．調(diào)度員盡力維護(hù)子系統(tǒng)發(fā)電、用電平衡時(shí)屬

A．正常狀態(tài)                                                        B．緊急狀態(tài)

C．恢復(fù)狀態(tài)                                                        D．瓦解狀態(tài)