依赖心理的主要表现方式有哪些？

已知四边形ABCD的对角线AC、BD相交于点O，给出下列5个条件：①AB∥CD；②OA=OC；③AB=CD；④∠BAD=∠DCB；⑤AD∥BC，从以上5个条件中任选2个条件为一组，能判定四边形ABCD是平行四边形的有（　　）组．

    Hello, my name is Betty and I'm in Class Six. I'm twelve years old. I'm American. I'm from New York. Mike is in my class and he is my good friend.

    Hi, I'm Mike. I'm from London. I'm in Class Six, too. Wang Tao is my friend. He is in my class.

    Hi, my name is Wang Tao. I'm Chinese. I'm from Hangzhou. I'm in Class Six with Betty and Mike. They are my good friends.

如图，四边形ABCD是菱形，∠A=60°，AB=2，扇形BEF的半径为2，圆心角为60°，则图中阴影部分的面积是（    ）