20天的美西行程是否合理?请高手指点指点。Day1:Los angelesDay2:Los angeles to Las vegasDay3:Las vegas to Idaho fallsDay4:Yellowstone: Bozeman住宿;Day5:Yellowstone: Cody住宿;Day6:Yellowstone: Jackson住宿;Day7:Yellowstone to Salt lake cityDay8:Salt lake city to BishopDay9:Yosemite: Mariposa住宿Day...