题型:选择题 题类:其他 难易度:中档
在直三棱柱\((\)侧棱垂直于底面的棱柱\()ABC-A_{1}B_{1}C_{1}\)中,平面\(α\)与棱\(AB\),\(AC\),\(A_{1}C_{1}\),\(A_{1}B_{1}\)分别交于点\(E\),\(F\),\(G\),\(H\),且直线\(AA_{1}/\!/\)平面\(α.\)有下列三个命题:\(①\)四边形\(EFGH\)是平行四边形;\(②\)平面\(α/\!/\)平面\(BCC_{1}B_{1}\);\(③\)平面\(α⊥\)平面\(BCFE.\)其中正确的命题有