如图,在\(⊙O\)中,\(AB\)是直径,\(D\)是\(⊙O\)上一点,\(C\)是弧\(AD\)的中点,弦\(CE⊥AB\)于点\(F\),过点\(D\)的切线交\(EC\)的延长线于点\(G\),连接\(AD\),分别交\(CF\)、\(BC\)于点\(P\)、\(Q\),连接\(AC.\)有下列结论:\(①∠BAD=∠ABC\);\(②GP=GD\);\(③\)点\(P\)是\(\triangle ACQ\)的外心;\(④AP·AD=CQ·CB.\)其中,正确的是________\((\)填序号\()\).