第一句： 描述背景(引子) it is indisputable fact that …
替换句型： it is an undeniable fact that …
it is an irrefutable fact that
第二句：(可有可无) the serious consequences of are often felt in our life .
第三句：承上启下：In this essay , I intend to explore the sources of this problem along with some possible solution to it .
替换句型： In the following essay , I aim to identify the sources of this problem as well as some viable solution to it .
第一句： Chief among the causes of this problem is ….
第二句： In the past , …
第三句： Consequently , …
第四句： Another major contributing factor is that …
第一句： In order to address its root causes. Perhaps the most effective method of doing this
would be for people to do sth.
第二句： Since …,
第三句： one further measure would be to …
替换句型： one further method of …would be for people to do
第一句： In conclusion , I believe that this is clearly a problem of such complexity that no solution is likely in the short term .
替换句型： In reality , this problem is unlikely to be resolved in the short term.
第二句： However , I believe that the measures outlined above would constitute a good first step .
However , it is by no means insurmountable , and I am convinced that …
替换句型： however , I believe that the hard way is sometimes that the best way .