参考答案：

The images above are both meaningful and instructive：this man’s hard work is not only for his own benefit，but also for the benefit of future generations．

The pictures serve to remind us that the existence of our current happiness and valuable national heritage is due to the struggles of our predecessors．We，in turn，should also work hard in order to guarantee the comfort and safety of generations to come．Sustainable development has become a topic of heated debate in recent years．While it is justifiable to satisfy current demands，we cannot neglect the needs of our descendants in the process．Our children also depend on Earth’s natural resources and we should not deprive them of such necessities．

Unfortunately，many people only think of their short-term，personal interests．An entire forest might be clear-cut，in the interest of making a profit，without a single tree planted in its place．This inconsiderate attitude towards the welfare of our descendants．as well the indifference to the outcome of such reckless actions，can only turn the earth into a cold and lifeless planet．People must be taught to appreciate the earth as not only their home，but also the home of our children and grandchildren，as well as all other plants and animals．

While making great efforts to increase our current quality of life，we must simultaneously consider how our actions will affect future lives.