答案:We should take a ride on one of its famous gondolas.
題目翻譯:我們應該做些什么才能完整地游覽威尼斯?
根據(jù)第二個小標題的第2-3行:
But no visit to Venice is complete without a ride on one of its famous gondolas, human powered water taxis.
但是沒有乘坐著名的貢多拉(人力水上出租車),威尼斯之旅就不算完整。
故答案為:We should take a ride on one of its famous gondolas.