在哪个朝代中秋节才开始成为固定的节日？
参考答案：
唐
If my lawyer ______ here last Saturday, he ______ me from going.
A．had been; would have prevented
B．had been; would prevent
C．were; would prevent
D．were; would have prevented
剩余价值在生产领域中产生，通过流通领域来实现。( )
