VOA慢速英语:UN: Opium Grown in Afghanistan Down by 48%

短语讲解：

1. The United Nations Office on Drugs and Crime says the amount of opium produced in Afghanistan has dropped by almost half compared to last year.

compare to 把…比作， 喻为; 与…相比
例句：We should compare to this problem more further the high opinion to that problem.
我们对这个问题应比对那个问题更加重视。

2. They also say less land is being used to grow opium poppy plants.

be used to 习惯于，适用于
例句：Petroleum can be used to produce various chemical products.
石油可用于生产多种化学产品。

3. But he says it increased in northern Afghanistan because of a breakdown in security in some places.

because of 因为，由于
例句：He is feeling wretched today because of the rain.
因为下雨，他今天情绪很不好。

4. Afghanistan produces more than 80 percent of the opium sold throughout the world.

more than 多于
例句：Rob likes apples more than bananas.
罗勃对苹果比对香蕉还喜欢。