【★★★when与where,which与when,填空+解释★★★填空1.I'llneverforgettheday___Ifirstwenttoschool.2.I'llneverforgettheday____wespentinBeijing.3.Isthisfactory___wevisitedlastweek?4.Thisisoffice___Lincolnonceworkedi】

　　★★★when与where,which与when,填空+解释★★★

　　填空

　　1.I'llneverforgettheday___Ifirstwenttoschool.

　　2.I'llneverforgettheday____wespentinBeijing.

　　3.Isthisfactory___wevisitedlastweek?

　　4.Thisisoffice___Lincolnonceworkedin.

　　选择

　　They'reintheplaces____couldn'tbefound.

　　a.thatb.wherec.inwhichd.inthat

　　请顺便为我讲解一下when与where,which与when在这类句子中有什么不同,为什么要那么选?