题目

Prices _______ sharply in the past few years. A have raised                 B. have been raisedC. have been risen          D. have risen    答案：C（2012•遂宁）如图，△ABC中，AB=AC=6，BC=4.5，分别以A、B为圆心，4为半径画弧交于两点，过这两点的直线交AC于点D，连接BD，则△BCD的周长是10.510.5．