1. There has been a discussionrecently abouot——.
2. It is obvious that——.
3. Additionally, ——.
4. So it is high time, ——
5. First of all, ——
6.The reason is——7.Secondly——
8.That is to say,——
9. Thirdly, ——.
10. In fact, more than three wayscan be adopted,——
11. As for me, ——
12. All in all, ——