某企业生产甲、乙两种产品，其单位利润分别是 300 元、200 元，该公司有两个机械加 工中心Ⅰ和Ⅱ，它们每天工作的有效工时分别为 20 小时、 18 小时。甲、乙产品都需经过这 两个中心加工， 生产每单位产品甲在加工中心Ⅰ需要 1 小时，在加工中心Ⅱ需要 3 小时。 生 产每单位产品乙在加工中心Ⅰ和Ⅱ各需要 2 小时和 1 小时。根据市场调查， 产品甲的日需求 量不会超过 5 单位，产品乙则无论生产多少都能售完。利润最大的生产方案是()。
A、每天生产产品甲42单位，乙86单位D
暂无解析
Directions:
Thissectionistotestyourabilitytounderstandshortconversations.Thereare2recordedconversationsinit.Aftereachconversation,therearesomerecordedquestions.Boththeconversationsandquestionswillbespokentwotimes.Whenyouhearaquestion,youshoulddecideonthecorrectanswerfromthe4choicesmarkedA,B,CandDgiveninyourtestpaper.ThenyoushouldmarkthecorrespondingletterontheAnswerSheetwithasinglelinethroughthecenter.
6、A.Thegoodsareoutofstock.
B.Sheismovingtoanothercity.
C.Thesalesseasoniscomingsoon.
D.Sheisafraidthepricewillgodown.
7、A.Bytrain.B.Byair.C.Byship.D.Bytruck.
8、A.Inthreeweeks.B.Intwoweeks.C.Nextweek.D.Nextmonth.
9、A.HRmanagerassistant.
B.Salesmanager.
C.Officesecretary.
D.Softwareengineer.
10、A.3weeks.B.6weeks.C.3months.D.6months.
下面哪些命令具有还原操作的作用
Directions:
Thissectionistotestyourabilitytounderstandshortdialogues.Thereare5recordeddialoguesinit.Aftereachdialogue,thereisarecordedquestion.Boththedialoguesandquestionswillbespokenonlyonce.Whenyouhearaquestion,youshoulddecideonthecorrectanswerfromthe4choicesmarkedA,B,CandDgiveninyourtestpaper.ThenyoushouldmarkthecorrespondingletterontheAnswerSheetwithasinglelinethroughthecenter.
1、A.Thereisnopaper.
B.Themancanusetheprinter.
C.Theprinterdoesn'twork.
D.Themanhastopayfirst.
2、A.Hehasgotanewjob.
B.Hehasgotapayrise.
C.Hehasbeenpromoted.
D.Hehasboughtanapartment.
3、A.Sellacar.
B.Rentacar.
C.Repairacar.
D.Buyausedcar.
4、A.Hedoesn'tlikethecolor.
B.Hedoesn'tlikethestyle.
C.Itistoosmall.
D.Itisofpoorquality.
5、A.Thechiefengineer.
B.Thereceptionist.
C.Theofficesecretary.
D.Thesalesmanager.
段落文字可以进行如下哪些操作（）
要删除所有打开的图象文件的历史记录，应采用下列哪个命令：
