1、If it continues like this, he expects levels of pollution to double over the next 15 years.
如果繼續(xù)這樣下去，他預期污染水平將在接下來的15年內(nèi)翻番。

2、Double over the map so that we can read it more easily.
把地圖對折起來, 這樣看起來更容易。

3、Demand for food is expected to double over the next forty years.
糧食需求預計在接下來的四十年翻一番。

4、Globally, the number of patients on dialysis is likely to double over the coming decade.
縱觀全球，透析治療的患者人數(shù)幾乎是近十年的兩倍。