四大洋: the Atlantic, the Pacific, the Indian, the Arctic 表示分數的詞: three quarters,two thirds,half 表示水域的詞: ocean,lake,pond,river, stream,spring 水的三種形態: solid,liquid,gas 自然界中的水: vapor, droplet, fog, dew, frost, cloud, shower,drizzle, sleet, hail depend on 取決于;依靠 run out of 用完 get rid of擺脫;除去 nothing but 只有;只不過 believe it or not 信不信由你 a variety of種種;各種各樣的 as 引導的時間狀語從句，例如: As rain falls and snow melts, waterflows downhill. whenever引導的時間狀語從句，例如: Your body loses waterwhenever you sweat or go to the bathroom. “that's why”句型，例如: That's why people check the weatherreport before deciding what clothes to wear and how to spend theday.