西亚地处“五海三洲”之地，其中三洲指的是欧洲、北美洲、南美洲。
读中东地区部分国家图和气候类型图，回答下列相关问题。
如图，在△ABC中，∠C=90°，AC=BC=4，D是AB的中点，点E、F分别在AC、BC边上运动（点E不与点A、C重合），且保持AE=CF，连接DE、DF、EF，在此运动变化的过程中，有下列结论：
①∠DEF是等腰直角三角形；②四边形CEDF不可能为正方形；
③四边形CEDF的面积随点E位置的改变而发生改变；
④点C到线段EF的最大距离为 2 ．
其中正确结论的个数是（ ）
(B)
Hi, friends! What do you like to do after school? In my school, we have different things (不同的事情) to do.
Mike does his homework (家庭作业) in the classroom. He likes doing his homework at school. The classroom building is in the middle of the school.
Lucy likes playing on the playground. Many students play there after school. The playground is behind the classroom building.
Jack likes reading books in the library after school. There are lots of books in our library. The library is on the left of the classroom building.
Students can play computer games in the science building. Peter likes playing computer games after school. The science building is on the right of the classroom building.
