问题补充：
The students were sitting in the classroom with their eyeson the teachers.
A. fixing
B. fixed
C. were fixed
D. being fixed
答案：
A. fixing
(答案→)B. fixed
C. were fixed
D. being fixed
解析：这是一个“with+名词+分词”的独立主格结构；因为“两眼凝视着……”的词组是fix one’s eyes on,可见one’s eyes 在该词组中是宾语，放在动词前应用被动语态。
