Read the following text and fill in the blanks with suitable words from the box. There are more words than needed. Make any grammatical change if necessary:

hang	sake	balance	ecology	link	alter	interrelated
ecosystem	know	responsible	rise	example	fixed	world

All things that make up the environment are (a) _________ .The way in which people, animals and plants are related to each other and to their surroundings is (b)_________ as ecology. The (c) ________ is a complex web that (d) _______ animals, plants and every other life form in the biosphere. All these things (e) ____________ together. The system is in a steady state of dynamic (f) ________ which means that by (g) __________ any one part of the web you can affect all the other parts. For (h) ___________ the destruction of forests may have serious (i) ___________ consequences. It is the (j) ___________ of human beings to prevent the environment from being spoilt.