一天,爱丽丝小姐给学生们布置了一道新的作业：幸福作业.要求学生们成为幸福的收集者,并观察他们把幸福带给身边的人时,会发生什么结果.由于这只是部分作业,全体学生都兴高采烈地完成了.但卡拉.查尔莫斯的所作所为令所有人大吃一惊.作业交上去几天了,卡拉背着一个大袋子出现在大家面前.On seeing this, everyone was filled with expectation, but Carla didn’t want to show anyone what was in the bag. Instead, she pulled out a small box and gave it to her teacher. When Miss Ellis had taken the box, Carla took a instant camera out of her own pocket and stood with it at the ready.见此情景，每个人都充满了期待。但卡拉却并不想让大家知道袋子里是什么东西。她拿出了一个小盒子递给了老师。爱丽丝小姐打开了盒子，卡拉从身上的口袋里取出了一架拍立得照相机，装在三脚架上。