①做好民族团结工作是一切工作的中心

②民族团结有助于国家稳定和社会发展

③维护民族团结就能实现民族共同繁荣

④维护民族团结是公民的神圣职责和光荣义务

阅读理解

    The summer vacation is over．Time always flies fast．During the vacation, the weather was hot and I couldn't do much work, but I lived happily．

    Because it was hotter in the afternoon, I did my homework in the morning．I got up at 6：30 am and took a walk in the garden for half an hour．

    After breakfast, I read English and Chinese and did some maths exercises．It took me three hours or more to finish my homework．I worked quite hard and made good progress．

    I spent the afternoon outside．I went to swim and it was fun．I came home at about five or six o'clock．Sometimes a friend of mine would come to see me, and we would spend some time listening to music．

    In this way I spent my vacation happily．I not only studied but also became a good swimmer．Now I'm in good health and in high spirits．

黑船事件后，日本陷入了半殖民地的危机之中。下列叙述不能说明这一问题的是()