float upward的用法和樣例：
例句
- Through hundreds of thousands of years, it has become so salty that salt crusts float upon it like ice.
經過千百萬年之後，其含鹽度變得極大，以至湖上浮著一層浮冰一樣的鹽殼。 - At sunset, long grasses crowned with white flowers invite moonlight to float in their waves.
黃昏的時候，長草頂著白花，邀月光在長草的波浪上浮遊。
