I didn’t know it could do terrible ______to your heart and lungs or ______was more difficult for smoking couples to become pregnant.

A．ruins; that

B．damage; it

C．damage; that it

D．sufferings; that this

学校购进一批粉笔，每箱36盒，学校买了12箱零20盒．这些粉笔一共有多少盒？