All around the world, people drink tea. But tea does not mean the same thing to everyone. In different countries, people have very different ideas about drinking tea.

    In China, for example, people always drink tea when they are getting together. They drink it at any time of the day at homes or in teahouses. They prefer plain tea, with nothing else in it.

    Tea is also important in Japan. The Japanese have a special way of serving tea called tea ceremony（茶道）. It is very old and full of meaning. Everything must be done in a special way in the ceremony. There is even a special room for it in Japanese homes.

    Another tea-drinking country is England. In England, the late afternoon is "tea time". Almost everyone has a cup of tea then. The English usually make tea in a teapot and drink it with milk and sugar. They also eat cakes, cookies and a few sandwiches at teatime. This is the so-called "Afternoon Tea" in Britain.

    In the United States, people drink tea mostly for breakfast or after meals. Americans usually use tea bags to make their tea. Tea bags are faster and easier than making tea in teapots. In summer, many Americans drink cold tea—"iced tea". Sometimes they drink canned iced tea, just as soda.

近年来随着环境危机的加剧，人们已越来越清醒地意识到，环境污染和生态失衡问题的解决，不能只依赖经济、法律和科技手段，还应诉诸哲学观念的变革，环境哲学也日益成为学界热点。这主要说明（  ）

补写出下列句子的空缺部分。