1)在开头出现;
2)在结尾出现;
3)在开头和结尾同时出现，首尾呼应;
4)有些文章的中心思想贯穿全文，并没有用一句话明确表达出来，这就要求学生学会归纳概括。
(三)实战演练
5 Many cities around the world today are heavily polluted. Careless methods of production and lack of consumer demand for environment-friendly products have contributed to the pollution problem. One result is that millions of tons of glass, paper, plastics, and these are difficult to get rid of.
However, today, more and more consumers are choosing “green” and demanding that the products they buy should be safe for the environment. Before they buy a product, they ask questions like these, “Will this shampoo damage the environment?” “Can this metal container be reused or can it only be used once?”
A recent study showed that two out of five adults now consider the environmental safety of a product before they buy it, this means that companies must now changed the way they make and sell their products to make sure that they are “green”, that is, friendly to the environment.
Only a few years ago, it was impossible to find green products in supermarkets, but now there are hundreds. Some supermarket products carry labels (标签) to show that the product is green. Some companies have made the manufacturing (生产) of clean and safe products their main selling point and emphasize it in their advertising.
The concern for a safer and cleaner environment is making companies rethink how they do business. No longer will the pubic accept the old attitude of “buy it, use it , throw it away, and forget it.” The public pressure is on , and gradually business is cleaning up its act.
What would be the best title for the text?
a. Business and People
b. Business Goes Green
c. Shopping Habits Are Changing
d. Supermarkets and Green Products