2010年6月我国网民数的同比增长率为（）。

A．9.4%

B．17.7%

C．24.3%

D．31.8%

Li Ming is ______ excellent student. He often gets to school ______ hour earlier than the other students.[ ]

A. an; an      

B. an; a    

C. a; the    

D. an; the