26．?dāng)?shù)據(jù)傳輸?shù)牟铄e控制方法有

A．循環(huán)檢錯法                                                    B．檢錯重發(fā)法

C．反饋檢驗法                                                    D．前向糾錯法

27．計算機網(wǎng)絡(luò)的拓撲包括

A．星形結(jié)構(gòu)                                                        B．總線結(jié)構(gòu)

C．環(huán)形結(jié)構(gòu)                                                        D．分布式結(jié)構(gòu)

28．配電管理系統(tǒng)的高級應(yīng)用軟件主要分成哪幾個層次

A．系統(tǒng)應(yīng)用軟件                                                 B．基本應(yīng)用軟件

C．派生應(yīng)用軟件                                                 D．專門應(yīng)用軟件

29．對負荷管理控制采用方式是

A．降壓減負荷                                                    B．升壓減負荷

C．用戶負荷周期控制                                          D．切除用戶可控負荷

30．連接局部網(wǎng)的中繼裝置有

A．轉(zhuǎn)發(fā)器                                                           B．橋

C．路                                                                  D．信關(guān)