有色物质的吸光度A是透过率T的倒数。（）
参考答案：错
Jack wasn't saying anything，but the teacher smiled at him ________ he had done something very clever.(2011·湖南)
A．as if
B．in case
C．while
D．thought
A．一张课桌
B．一本物理课本
C．一支铅笔
D．一个中学生
