“家天下”制度是历史的进步，主要是因为（  ）

A．代表了先进阶级的利益

B．是生产力发展的结果和社会进步的要求

C．是文明时代开始的标志

D．是华夏民族开始形成的标志

-There is a mobile phone on the desk. Is it Li Yong's?

-It __________ Li Yong's. He went to Shanghai two days ago.[ ]

A. can be

B. can't be

C. must be

D. might be