【题目】It was ___struggle for him to finish _______experiment, with the room in ________mess after he finished it.
A.the; an; /
B.a; the; a
C.a; an; /
D./; the; a

【答案】B
【解析】句意：完成这个实验对他来说是一次折磨，他完成之后房间里一片混乱。“struggle”是泛指，用a ；“experiment”是特指，用the；in a mess“一片混乱”，故选B。