题目

完形填空It’s very important that we all recycle.In nature,everything ________ again.For example,when an animal dies,it becomes ________ animal’s food.Nothing is wasted.But humans have created things like plastic bags which can’t be ________ down by nature.Our ________ kills animals and pollutes water and soil. ________ we continue making too much rubbish,the problem will only get worse.If nature can’t reuse the rubbish,we must recycle ________ .We should clean up the rubbish we’ve made because nature can’t.Recycling is also the right thing to do for another reason.The earth i测量较小物体的长度，一般要用______作单位；测量较长的路程，应该用______作单位．