第一册课本听力(上)Unit10 integrating skills

　　Without air, water and sunlight there would be no living things. Because they are so important, ecosystems¹ try to be very careful with these valuable resourses. Human beings often throw away things they have used only once. In good ecosystems, resources are used many times. The waste of plants and animals will become food for another. In fact, nature is much better at recycling than we humans are. Maybe we should learn from nature and become better recyclers—if we throw away too much, we may be throwing away our future.
We all care about nature and the environment, but we may not always do everything we could or should. Scientists who know a lot about the environment say that we should " Reduce, Reuse, Recycle and Respond". Let's see what that means.

1 ecosystems   

n.生态系统( ecosystem的名词复数 )

参考例句：

• There are highly sensitive and delicately balanced ecosystems in the forest. 森林里有高度敏感、灵敏平衡的各种生态系统。 来自《简明英汉词典》
• Madagascar's ecosystems range from rainforest to semi-desert. 马达加斯加生态系统类型多样，从雨林到半荒漠等不一而足。 来自辞典例句