Li Ming is _____, He would like some rice. [ ]
A. hungry
B. thirsty
C. tired
答案:A
Classification is a useful ______ to the organization of knowledge in any field.
A.means
B.approach
C.mode
D.manner
在岸上看到湖水的深度比实际的浅,这是由于( )
A.光的直线传播
B.光的反射
C.光的折射
D.以上都不是