①应学会躲避坏人侵害的本领
②应学会运用法律武器维护自己的合法权益
③女学生要衣着打扮得体、行为举止文明
④要敢于向司法机关揭发检举违法行为
A:①③④
B:②③④
C:①②③
D:①②④
如图,△ABC中,∠C=90°,点G是线段AC上的一动点(点G不与A、C重合),以AG为直径的⊙O交AB于点D,直线EF垂直平分BD,垂足为F,EF交BC于点E,连结DE.
(1)求证:DE是⊙O的切线;
(2)若cosA=12,AB=83,AG=23,求BE的长;
(3)若cosA=12,AB=83,直接写出线段BE的取值范围.
—Look, she ____ (talk) with her students over there.
印度新兴的高科技工业中心分布在( )
You'd better not ask him about the problem. He's new here and he knows ______ about it.