《左传》记载：“天子建国，诸侯立家，卿置侧室，大夫有贰宗，士有隶子弟”。西周时维持这一体系的制度是

A．分封制

B．宗法制

C．等级制

D．世袭制

—Which driver was to blame?

—Why,_____!It was the child’s fault,clear and simple.He suddenly came out between two parked cars.

A．both

B．each

C．either

D．neither