21.不變動(dòng)原代碼體系，就可直接追加新代碼的設(shè)計(jì)原則，反映了代碼設(shè)計(jì)的(　　　)

A.易識(shí)別性                                                      B.合理性

C.可擴(kuò)充性                                                      D.規(guī)范性

22.在面向?qū)ο笤O(shè)計(jì)中，使用對(duì)象時(shí)只需要了解對(duì)象的(　　　)

A.數(shù)據(jù)描述                                                      B.實(shí)現(xiàn)方法

C.過程程序                                                      D.接口功能

23.在規(guī)劃設(shè)計(jì)用戶菜單時(shí)，建立可執(zhí)行文件的操作稱為(　　　)

A.創(chuàng)建                                                             B.確定任務(wù)

C.生成                                                             D.運(yùn)行測(cè)試

24.需要隨意打開某個(gè)用戶快捷菜單時(shí)必須(　　　)

A.單擊右鍵                                                      B.雙擊左鍵

C.單擊左鍵                                                      D.按設(shè)定鍵

25.如果要求數(shù)據(jù)輸入成本低、方便、靈活，應(yīng)當(dāng)采用的輸入設(shè)備是(　　　)

A.條碼機(jī)                                                         B.鍵盤

C.觸摸屏                                                         D.光筆