A:had always been warned
B:were always being warned
C:are always warning
D:always warned
设集合A=x|-1≤x≤2,B=x|0≤x≤4,则A∩B=( )
①尊重他人是一个人内在修养的外在表现 ②要学会徒有其表的作秀
③尊重能促进社会进步,提高社会文明程度 ④得到他人的尊重会产生自卑感
(Ⅰ)求曲线Γ的方程;
(Ⅱ)设动直线l交曲线Γ于E、F两点,且以EF为直径的圆经过点O,求△OEF面积的取值范围.