参考答案：

As can be seen from the picture, with the" advance" of houses, the trees"retreat". Obviously, the drawer is trying to focus our attention on a very serious problem: the explosion of housing endangers the existence of trees.

With the rapid increase of population, we have to build more and more houses to meet people’s need. As a result, more trees will have to be cut down to make room for more buildings. It is known to all that trees are essential for human living. Besides providing us with wood and food, trees can help absorb dioxide and give off oxygen. Trees can also help moderate climate and ensure us a cozy living environment. We may say that the peace and beauty of woods are indispensable to man’s wellbeing. Life would be unimaginable without trees.

From the condition of trees, I firmly believe that ways must be found to stop cutting trees ruthlessly. Good planning has to be worked out to avoid cutting trees. Most importantly, we should plant more trees and give them meticulous care. To ensure a better life for later generations, we should become keepers instead of destroyers.