21.Greatchanges____intheCityofGuangzhousince1980,andalotofbigbuildings____.A.weretakenplace,weresetupB.havetakenplace,havesetupC.havetakenplace,havebeensetupD.havebeentakenplace,havebeensetup22.Thepen____quitesmoothly.A.writesB.iswritingC.canbewrittenD.iswritten23.Water____intosteamifitisheatedtoitsboiling鄄point.A.isgoingtobeturnedB.willbeturnedC.hasbeenturnedD.isbeingturned24.—Isawthatnewfilmyesterday.—Didyou?I____itye...