北京地区每年夏季盛行[ ]
A、东北季风
B、西北季风
C、西南季风
D、东南季风
答案：D
A vast area north of the Yangtze River ______by the first heavy SNOW of the new year，causing difficulties to the post-festival road transport.
A．were affected
B．was affected
C．had affected
D．has affected
公安机关只是我国国家的治安行政力量。( )
