确立二战后世界两极格局基本框架的是[ ]

A． 雅尔塔体系         

B．杜鲁门主义

C．马歇尔计划           

D．北大西洋公约

There was a traffic jam; otherwise I ____ here on time.

A．would be

B．had been 

C．should be

D．would have been