已知在Rt△ABC中,斜边AB=2BC,以直线AC为对称轴,点B的对称轴是B',如图所示,则与线段BC相等的线段是____,与线段AB相等的线段是____和____,与∠B相等的角是____和____,因此可得到∠B=____.
Lucy likes English very much . She does her best _____it well.
My sister likes playing the guitar, but she can't play ______.
在中国封建社会, 重农抑商政策被视为“国策”,洋务运动标志着清政府放弃了重农抑商政策,开始发展工业。在洋务运动中,洋务派最成功.最有远见的举措是( )
下列关于鸟类的结构叙述中,哪一项是错误的?( )