开头段引起下文
There are many reasons that can verify this.
There are three premier causes as follows.
Among countless factors which influence my decision, there are three conspicuous aspects.
Admittedly, there are merits to both sides of the argument.
Before rendering my opinion, I think it is important to take a glance at the arguments on both sides.
On such a controversial issue, people seldom reach an absolute consensus.
This issue is so controversial that people can hardly reach an absolute consensus.
It is quite understandable that views on this issue vary from person to person.
It is crucial that we analyze the causes of this disturbing issue and explore effective solutions. From my own perspective, the causes are multiple.