考察翻译: 

A选项A lesson that we can draw from this example is quite obvious.….. 由这个例子我们能得出一个非常明显的结论...

B选项In one word,…….总之...
C选项 Based on the above reasons, I firmly believe that …...基于以上原因, 我坚信.... 

D选项All in all, I think …….总而言之, 我认为...