定義： A landform consisting of loose rock particles such as sand, gravel, shingle, pebbles, cobble, or even shell fragments along the shoreline of a body of water.
定義： a plant that produces wood as its structural tissue. Wood is a structural cellular adaptation that allows woody plants to grow from above ground stems year after year, thus making some woody plants the largest and tallest terrestrial plants. Wood is usually primarily composed of xylem cells with cell walls made of cellulose and lignin
