如图，边长为1的正方形ABCD绕点A逆时针旋转45°后得到正方形AB₁C₁D₁，边B₁C₁与CD交于点O，则四边形AB₁OD的面积是（　　）

先通读下面的短文，掌握其大意，然后从A、B、C、D四个选项中选择可以填入空白处的最佳答案。

    Hello，everyone!My name is Tony．Welcome to our school lost and found1．You can always2 some books or other things somewhere in me school because of the some careless(粗心的)students．Some students3 them and send them here．

    Look!There is a nice pen.There's also a black bag4some books in it.Oh,here is Kate's 5on the bag.I think it's6．Look at the pencil case(铅笔盒)．There is a pen and two erasers in it．Under the table there are two7．Some boys like 8basketball after class．The basketballs are theirs,I think．Look at the cute toy dog．I don't know9 it is．

    So everyone，be10your things．

①中国的进步积极推动着世界的和平与发展

②中国是一个重承诺、守信誉、讲原则的国家

③和平发展战略和道路赢得了世人的理解

④响应和支持中国终究会登上超级大国的地位

关于欧盟的叙述，错误的是（    ）