1、开头：

（1）“如今，人们普遍认为......,但是我怀疑......

Nowadays，it is generally/commonly believed that......, but I wonder that......

（2）“如同硬币的正反面，......也有积极的一面和消极的一面。

Like a coin has two sides, there is a positive aspect and a negative aspect to......

（3）“近来，......的问题已经成为人们注目的焦点。”

Currently, the issue of......has been brought to public attention

（4）“随着......的快速增长，......在日常生活中已经变得越来越重要。

Along with the rapid growth of......,......has become increasingly important in our daily

（5）“由汽车(或xx）引起的空气和噪音污染对我们的健康造成了危害。”

Air pollution and noise pollution caused by automobiles do harm to our health.

2、结尾：

（1）“因此，不难得出结论......”

Accordingly/Consequently/As a result,it is not difficult to draw the conclusion that

（2）“综上所述，我们能得出如下结论......”

From what has been discussed above, we may reasonably arrive at the conclusion that......

（3）“这一难题，是任何人都不可能避免的。但只要处理得当，我们就会......”

The dilemma is something no one can avoid. Properly handled, however, we will

（4）“总之，全社会都应该密切关注......,只有这样我们才能......”

All in all, the whole society should pay close attention to the problem of....... Only in this way can we.......

（5）“考虑到所有的因素，我们意识到......

Taking into account all of these factors, we have reached the realization that......