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。

    Edward has a pet dog and his name is Liston．Every day he1Liston for a walk in the park．He loves his dog very much．

    This morning，Edward has to go to the art club．So he goes to Liston and says．"I will come back2soon(很快)，Liston．Just stay in the garden and sleep3the tree．"And then Edward goes to the4station and gets on the bus．

    Liston doesn't want to 5Edward．He runs after Edward quietly．6the bus goes too tast,so Liston has to stop．

    After Edward comes home,he runs into the garden to7Liston and play with him．"Liston! Liston !8are you?"he shouts．But he can't see his dog．

    Edward walks up and down the street and calls dog's9．Then he hears(听到) Liston's bark(吠声)．"Liston!Liston!I'm here．" Liston runs to Edward10．Liston was waiting for him near the station．

已知两定点A（2，5），B（﹣2，1），M（在第一象限）和N是过原点的直线l上的两个动点，且|MN|=2$\sqrt{2}$，l∥AB，如果直线AM和BN的交点C在y轴上，求点C的坐标．

某历史兴趣小组收集了下面这样一组图片进行探究学习，你认为他们学习的主题应该是（    ）