52. The next morning the first thing my brother and me did was to go out for a walk in the forest.

解析：第二天早上，我和哥哥做的第一件事是去树林散步。
在my brother and me did这个宾语从句中，my brother and me是做主语，me不能用宾格形式，应该改为my brother and I，答案选择B。正确句子应该是The next morning the first thing my brother and I did was to go out for a walk in the forest.