— Look at the boy playing basketball on the ground. Is it George?

— It ________ be him. He told me he would play basketball after class, but he’s not sure.

A．mustn’t

B．must

C．can’t

D．may

下列属于相对性状的一组是 [ ]

A．黄色玉米粒和白色玉米粒

B．人的身高和人的体重

C．山羊的短毛和绵羊的长毛

D．辣椒的绿色和番茄的红色