The computer (had just been turned on )when his cell phone rang .为什么用完成时态而不用过去式 （was just turned on)

I have opened the computer为什么不用I had opened the computer He ________ the computer for half a year. A.has bought B.had bought C.has had D.had had the computer Finally,they had to take this computer to the computer service center.翻译翻译成中文.请求学者 My brother turned off the computer after he had finished _（write） the Email. richaid turned off the computer after he had finished什么the e.mail Each key of the computer ________ a letter,number or word.A.have B.has C.had D.has had The old computer _______(break) down easily,so I had to restart it again and again. How long have they _____ the computer?A.bought B.had C.borrowed D.sold The old computer __(break)down easily,so I had to restart it again and again. they overcame a lot of difficulty they had developing the personal computer怎么翻译 The computer -----by him for three years?A was kept B has been had i have had the computer ____many years A since B in C for D / 被动语态和过去完成时The computer was invented in 1800可以转换为The computer had beed invented in 1800么? ---Is this the computer you ____last week?---That is it A.had it repaired B.repaired itC.had repaired D.had repair David failed the exam againif only he had spend as much time as he___on computer games为什么填did? Richard turned off the computer after he had finished___the emailA.write B.to write C.writing D.wrote 那However,someone had to first problem the computer with intructions and that took many hours怎么翻