Nowadays, there exists an increasingly serious social/economic/environmental problem. ________(具體的社會問題或者現象)has increasingly become a common concern of the public. According to a survey, ________(說明這種現象的情況或者舉一個例子).
There are a couple of reasons behind this problem/phenomenon. For one thing, ________(理由一); for another, ________(理由二). What is more, ________(理由三).
Based on the above discussions, I can easily forecast that more and more people will ________(作出某種反應).
Nowadays, there exists a common phenomenon：with the development of the Internet, more and more people tend to send electronic cards instead of paper ones to their friends and relatives when an important holiday comes.(具體現象)
There are a couple of reasons behind this phenomenon. For one thing, compared with the traditional cards, electronic cards are livelier and more interesting. They can give not only pictures but also sound and animations. For another, there are many websites online which offer varieties of cards to you to choose from. What is more, with the popularity of the electronic cards, less paper is used in making paper cards, which does good to our environment.(理由)
Based on the above discussions, I can easily forecast that sending greetings by using electronic cards will be accepted by more and more people.(預測前景)
例如想表達“郵遞員天天準時到”，如果寫成The postman comes on time every day，就不如變成雙重否定，The postman never fails to come on time，就變成了亮點句，起到強調作用。
“幾乎每個人對生活的態度都不同程度受到地震的影響”，寫成雙重否定There was hardly a man or a woman whose attitude towards life had not been affected by the earthquake.