Our teacher entered the classroom, .
A. a book in hand
B. book in hand
C. book in his hand
D. a book in hands
网友回答
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。