单项选择题
A. 12:28am on May 25,1999
B. 12:28pm on May 25,1999
C. 5:25am on December 28,1999
D. 5:25pm on December 28,1999
单项选择题 Whichofthefollowingproblemshasoccurredwhenamenuappearsandpromptstheuserto"copyadumptoexternalmedia?（）
单项选择题 Afilenamed"core"existsinthecurrentdirectory.Whichofthefollowingcommandsshouldbeusedtodeterminewhatcreatedthe"core"file?（）
单项选择题 Whichofthefollowingoptionsindicateswhyitisimportanttotalktotheuserandaskappropriatequestionsaboutasoftwareproblem?（）
