John Clark was a postman. He was fond of dogs. However, when he was delivering（投递）letters, he found that 1dogs were his friends. One particular dog called2, who lived at No.108 Turner Road, was one of John's 3. Whenever John came near his 4house, Spot would lie in and 5out on John, barking（吠叫）and trying to 6his ankles.

    After a heavy snow,7was freezing that morning. The road was covered with8. John was afraid of 9 down, so he10his bike and walked with11steps. Unfortunately, John slipped on a patch of ice, which was opposite to No.108 Turner Road. Spot12this as John together with his bike made such a big noise.Spot jumped onto John's 13and tried to bite his neck.Quick as a flash, John,14hands were full of letters, bit15on the leg.

    John Clark said later, it was the 16thing I could do.I don't approve of（赞成）17to animals, but that dog18 had it coming. Since that day I've had no 19at No.108.Spot always hides round the 20of the house when he hears me coming.

材料一：1924年1月，国共两党合作正式形成。……孙中山拟定的最重要的措施，是在黄埔建立一个训练军官的军事学校，进行标准化的军事训练和向学生灌输共同的革命思想。……北伐军向全世界发表声明，说明了北伐的爱国目的：从军阀手中解放中国，赢得在各国中的正当的平等地位。

——（美）费正清《剑桥中华民国史》

材料二：（卢沟桥事变后）在中华民族面临生死存亡之际，国共两党再度合作。团结一致，同仇敌忾成为中华民族的共识。……抗战时期，***人以民族的根本利益为重，顾全大局，抛弃前嫌。早在1936年处理西安事变时，***就力主和平解决

材料三：中华民族不畏强敌，不怕牺牲。……（在某次战役中）八路军作战1800余次，毙伤日、伪军2．5万多人，破坏铁路470多千米，公路1500多千米，桥梁和隧道260多个，一度恢复县城四五十座，并缴获大量武器。淞沪战役中，守卫宝山的500名官兵与敌巷战肉搏，全部壮烈殉国。

——材料二，三摘自《光明日报》：《抗日战争时期的中华民族精神》

材料四：廖承志认为：“国共两度合作，均对国家民族作出了巨大贡献。”

凡尔赛—华盛顿体系的积极作用表现在（    ）