—I didn't go to bed ________ 12 o'clock last night because there was too much homework.
A:until
B:though
C:after
D:beside
图是某发达国家与某发展中国家人均GDP和人口密度示意图。下列工业中,最可能由甲国转移至乙国的是( )
如图,在△ABC中,AB=AC,DE是过点A的直线,BD⊥DE于D,CE⊥DE于点E;
(1)若B、C在DE的同侧(如图所示)且AD=CE.求证:AB⊥AC;
(2)若B、C在DE的两侧(如图所示),其他条件不变,AB与AC仍垂直吗?若是请给出证明;若不是,请说明理由.
3+6=____