(1) "Juan" vividly describes the rapid situation when a shower strikes. "Roar" describes the momentum of showers from the perspective of hearing. (2) "Sudden Sunny" writes that the rain comes and goes quickly, and the poem disappears. "The mountain is green" describes the changes of the scenery before and after the rain, suggesting that the shepherd boy is relaxed because of the rain. (That's right)

(3) Not good. The shower at the beginning echoes the rain stop, which reflects the artistic ingenuity of the author's layout. If the fifth and sixth sentences are put at the beginning, the shepherd boy becomes the focus of description, which dilutes the artistic effect of the poem.

All right. The first is to write about the carefree situation of the shepherd boy, to set off the tense scene of sudden heavy rain, to provide readers with a reading perspective and enhance the immersive artistic effect. According to the present order, it is slightly abrupt in expression. (reasonable)