All the students could tell the teacher was surprised from the__

All the students could tell the teacher was surprised from the_______off his face.
A、appearance
B、shock
C、sight
D、expression
【正确答案】：D
【题目解析】：appearance 外表；shock 震惊；sight 视力；expression 表达，表现句意；从老师脸上的表情可以看出，所有的学生都很惊讶。