VOA慢速英语:Aquaponics Combines Growing Vegetables and Within Fish

短语讲解：

1. At least half of the world's food fish are raised in farms, waste from all those fish causes pollution.

at least 至少
例句：Read at least 30 books.
至少读30本书。

2. There are fewer and fewer fish in the ocean and more and more fish will be raised on farms.

more and more 越来越; 越来越 ...; 日益
例句：As time passed, the group spent more and more time inside.
渐渐地，学习小组在室内的时间越来越长。

3. They grow well in greenhouses in the winter, and where also you gonna get a fresh red romaine, and this is grown locally in a greenhouse in the middle of the winter.

in the middle of 在…的中间
例句：It landed smack(-dab) in the middle of the carpet. 
那东西正好落在地毯的中央.