{{i}}quEstions 19-22 ArE BAsED on thE Following DiAloguE:{{/i}}

how mAny solAr hEAt pAnEls Do thrEE or Four-BEDroom homEs usuAlly nEEDA．thrEE or Four.
B．FivE or six.
C．sEvEn or Eight.
D．twElvE or morE.