—What happened? I called you several times yesterday evening, but I couldn't get through.

—Sorry, my sister and I ________ on the phone all the time.

A．talked

B．have talked

C．were talking

D．have been talking

某博物馆的门票售价为成人票5元，孩童票4元。两位购买全票的成人可免费带一位小孩入馆，任何五个人的团体可以购买总价为19元的特价门票。现有三位成人带领十四位小孩进馆参观，请问他们购买门票至少要花费多少元( )

A．65元
B．64元
C．58元
D．52元