1.开头
Look at this picture.The picture shows that...From this picture, we can see...As is shown in the picture...As is seen in the picture...
2.衔接句
As we all know, ...As is known to all,...It is well known that...In my opinion,...As far as I am concerned,...This sight reminds me of something in my daily life.
3.结尾句
In conclusion...In brief...On the whole...In short...In a word...Generally speaking...As has been stated...