If December 26's tsunamis   have taught us anything, it is that nature does not recognize national boundaries  . The same can be said of a lot of many other problems facing human beings. Global warming, for example, will affect the whole world. Similarly, diseases like AIDS or SARS can spread rapidly from country to country. At no other time in human history has it been so urgent   for humans to recognize that they need to learn to stick together. If they don't, the chances are that they will soon find themselves alone. What will it take to get humans to take this truth seriously? Disaster seems to be a good way of  _ . The tsunamis, for example, have opened the hearts of countless numbers of people all over the world who offered their immediate help. But why can't they come together to avoid a disaster that they know will occur if they do not act in time? One of the reasons is a lack of imagination. Most people can readily understand, for example, how rising global temperatures can melt the polar ice-cap, raise sea-levels, and greatly change global weather. But these changes will not occur overnight. And people find it difficult to imagine changes that will occur in stages, slowly, and over years. So they pay little attention to the problem. They hide their heads in the sand. They think that something, somehow, will come to make the problem disappear.  The Indian Ocean tsunami killed tens of thousands of people and left millions homeless. Diseases may kill many more if clean water supplies are not provided in time in the disaster areas.  But already the disaster has revealed   some good things: One, there is more goodwill and kindness in the world than we are likely to believe. And two, the world is indeed capable of coming together as one in the face of the disaster. We pray that some of this spirit runs over into 2005. There are many disasters -- man-made, not natural ones -- that might be avoided if the world can learn to stick together. The reason why people pay little attention to disasters beforehand is that   _  .
they are not advised to take actions they hardly realize hidden disasters will happen suddenly they think others can solve the problem they believe disasters will disappear with no reasons