单选题：回答题Earth is the only 21 we know of in the universe that ca

回答题
Earth is the only 21 we know of in the universe that can support human life.22 human　activities are making the planet less fit to live on．As the western world 23on consuming two-thirds of the world's resources while half of the world's population do so 24 to stay alive．We are rapidly destroying the25resource we have by which all people can survive and prosper．Everywhere fertile soil is 26built on or washed 27 the sea．Non-renewable resources are exploited so much that they will never be able to recover 28 ．We discharge pollutants into the atmosphere without any thought of the consequences．As a 29 the planet's ability to support people is being 30 at the very time when rising human numbers and consumption are 31 increasingly heavy demands on it．The Earth's32resources are there for us to use．We need food, water, air, energy, medicines, warmth, shelter and minerals to 33 us fed, comfortable, healthy and active．If we are　sensible in how we use the resources they will 34 indefinitely．But 35 we use them wastefully and excessively they will soon run out and everyone will suffer．
A．situation
B．place
C．position
D．site