如图\(1\),矩形\(ABCD\)中,\(AD= \sqrt {3}.\)点\(E\)在\(AB\)边上,\(CE⊥DE\)且\(AE=1.\)如图\(2\),\(\triangle ADE\)沿直线\(DE\)向上折起成\(\triangle A_{1}DE.\)记二面角\(A-DE-A_{1}\)的平面角为\(θ\),当\(θ∈(0^{\circ},180^{\circ})\)时,
\(①\)存在某个位置,使\(CE⊥DA_{1}\);
\(②\)存在某个位置,使\(DE⊥A_{1}C\);
\(③\)任意两个位置,直线\(DE\)和直线\(A_{1}C\)所成的角都不相等.
以上三个结论中正确的序号是\((\) \()\)