图示桁架B点竖向位移（向下为正）△<img src="/Image1/18/1890ac2f34e312766531c4b4d5a1129d.jpg" />为：（）<img src="/Image1/b2/b218340948872cf0ba479bb1956d49cf.jpg" /><br>A:[（4+2<img src="/Image1/6a/6a946cc9da991b8deb04cde5360cc170.jpg" />）／EA]pa<br>B:[（-4+2<img src="/Image1/6a/6a946cc9da991b8deb04cde5360cc170.jpg" />）／EA]pa<br>C:[（2+2<img src="/Image1/6a/6a946cc9da991b8deb04cde5360cc170.jpg" />）／EA]pa<br>D:0