单项选择题
A．All living creatures die in order to be eaten by others. B．All living creatures can be the food of others. C．All living creatures decay. D．Only a small number of living creatures can avoid being eaten by others.
A．governments B．modern technology C．our rivers and forests D．the United Nations
A．arsonists set matches to leaves B．crude oil contacts inflammable objects C．tourists throw cigarette ends onto refuse dumps D．trees start burning of themselves