已知\(\Delta ABD\)和\(\Delta BCD\)是两个直角三角形,\(\angle BAD=\angle BDC=\dfrac{\pi }{2}\),\(E\)、\(F\)分别是边\(AB\)、\(AD\)的中点,现将\(\Delta ABD\)沿\(BD\)边折起到\({{A}_{1}}BD\)的位置,如图所示,使平面\({{A}_{1}}BD\bot \)平面\(BCD\).
\((\)Ⅰ\()\)求证:\(EF/\!/\)平面\(BCD\);
\((\)Ⅱ\()\)求证:平面\({{A}_{1}}BC\bot \)平面\({{A}_{1}}CD\);
\((\)Ⅲ\()\)请你判断,\({{A}_{1}}C\)与\(BD\)是否有可能垂直,做出判断并写明理由.