①坚持了矛盾分析法这一认识事物的根本方法
②重视事物内部矛盾对事物发展的决定性作用
③强调事物的外部矛盾是事物发展的必要条件
④突出了个人在历史发展中所起的关键性作用
A:①②
B:③④
C:①④
D:②③
Anne and Sue are good f____. They have the s____ age. They are both twenty-two. They both like sports. Most important, they both like new dresses. They usually go s____ together at weekends. Now they are in a c____ shop. There are d____ kinds of beautiful dresses. Anne wants a red dress. But Sue thinks the pink o____ is better.
如图,AB是⊙O的直径,弦CD⊥AB于H.点G在⊙O上,过点G作直线EF,交CD延长线于点E,交AB的延长线于点F.连接AG交CD于K,且KE=GE.(1)判断直线EF与⊙O的位置关系,并说明理由;(2)若AC∥EF,AHAC=35,FB=1,求⊙O的半径.