While boating on the lake, I saw young people swimming in the river. I remembered that my father often said when we were young, we swam in the river in front of our house. There was no swimming anywhere. I feel a little envious when I see people here swimming in the river without any scruples. I envy them that there is no pollution here, no need to worry about smog, and the mountains are clear and the water is beautiful. I think although people here may have poorer material conditions, their life happiness index should be very high. The scenery along the way is refreshing.