—My parents only allow me to read paper books. They my eyes.
A:talk about
B:hear about
C:learn about
D:worry about
如图所示,有人在种植床上种农作物,鱼缸内养鱼,自创循环生态.鱼缸中的水被水泵定时抽上来,水和鱼的粪便滋养了种植床上的农作物,水经种植床和农作物过滤后流回鱼缸.下列有关叙述中,正确的是( )