The light is on in his room.He___back.Awill be Bis Ccan be Dmust be

问题描述:

The light is on in his room.He___back.Awill be Bis Ccan be Dmust be
理由

D
He must be back.他肯定回来了.
表示肯定的猜测.否定的猜测用:can't be