将因征地而导致无地的农民，纳入统一的失业登记制度和城镇就业服务体系，并建立社会保障制度是属于( )。

A．货币安置

B．保障安置

C．重新择业安置

D．农业生产安置

We had to wait half an hour _____ we had already ordered a table.[ ]

A. since

B. although

C. until

D. before