.Who is the person ____is talking about the accident ___happened on Highway 104?

The old house we paid a visit _____ at thetop of the hill.

When she passed the room, the nurse noticed the old lady _______ to get out of bed.

下列词句中，划线成语使用正确的一项是（ ）

Look! Our headmaster is standing at the school gate.–It _______ be our headmaster. He is taking a student to the hospital now.