— They are quiet , aren't they?

— Yes. They are accustomed_________at medls.     [      ]

A. to talk                      

B. to not talk  

C. to talking                    

D. to not talking

某校下午2点整派车去某厂接劳模作报告，往返需1小时，该劳模在下午1点整就离厂步行向学校走来，途中遇到接他的车，便坐上车去学校，于下午2点40分到达，问汽车的速度是劳模的步行速度的多少倍( )

A．5倍

B．6倍

C．7倍

D．8倍