经肠道传播的肝炎病毒（）
A.HAV
B.HDV
C.HCV
D.HEV
E.HBV
参考答案：A, D
教室里不同位置上的同学都能看到黑板上的粉笔字，这是光的__ __缘故.（填“镜面反射”或“漫反射”）
There are _____ people here in the city. But only _____ people of them are Chinese. [ ]
A. million of; two millions
B. millions of; two million
C. millions of; two millions
D. million of; two million
