Nobody believed his reason for being absent from classhe had to meet his uncle at the airp

问题补充：

Nobody believed his reason for being absent from classhe had to meet his uncle at the airport.

A. why

B. that

C. where

D. because

答案：

A. why

(答案→)B. that

C. where

D. because

解析：that在此引导同位语从句，修饰名词his reason。此题的难点是，his reason后带有用作定语的介词短语for being absent from class，如果撇开这个介词短语，问题就变得简单了。