A:OD
B:OF
C:OA
D:OC
(Ⅰ)求证:BG∥面ADEF;
(Ⅱ)求证:面DBG⊥面BDF.
⑴ ____ ⑵ ____⑶ ____
已知集合A={﹣1,0,a},B={x|1<2x<2},若A∩B≠∅,则实数a的取值范围是____