Our teacher entered the classroom .A. a book in handB. book in handC. book in his handD.

问题补充：

Our teacher entered the classroom, .

A. a book in hand

B. book in hand

C. book in his hand

D. a book in hands

答案：

A. a book in hand

(答案→)B. book in hand

C. book in his hand

D. a book in hands

解析：考察复合结构。with a book in his hand= a book in hand;句意：我们的老师进入教室，手里拿着书。