解释：注视，凝视
用法：fix one's eyes on ／ upon sth.
例题：
The teacher's eyes, without any expression, _____ the boy who made faces.
A. watched B. stared at C. glared at D. were fixed upon
D.watch,stare,glare的主语只能是人,只有D构成fix one's eyes on ／ upon sth.