whAt is thE mAin purposE oF thE rEsEArCh
A、to mAkE prEpArAtions For A nEw puBliCAtion.
B．to lEArn how CouplEs spEnD thEir wEEkEnDs.
C．to know how housEwork is shArE
D、
D、to invEstigAtE whAt pEoplE Do At thE wEEkEn
D、