434. To sum up, given all the reasons discussed above, we can safely reach the conclusion that the earth is being harmed by human activity.
本句是建议型的结尾段落。To sum up一般是结尾段的信号词，表示总结，也可以使用In summary、To summarize、In sum、In brief、In short、In a word、In a nutshell、All in all、Generally speaking等表示结论。we can safely reach the conclusion that...后接同位语从句，陈述作者的结论。
In conclusion, I believe that it's better to be a leader of a group rather than an ordinary member.
In summation, I much prefer classes where the students do some of the talking.
My conclusion is that the best way to develop one's skill is to put theoretical knowledge to practical use in the real world.
I can draw the conclusion that universities should not, and do not need to, spend the same amount on their sports activities as on their libraries.