A driver should ________ the road when _________.

A．concentrate on; drive

B．concentrate in; driving

C．concentrate to; drove

D．concentrate on; driving

构成社会制度的基本要素是( )

A．价值要素和组织要素
B．价值要素和规范要素
C．规范要素和组织要素
D．规范要素和设备要素