Today, people are using too many natural resources andproducing too much waste. These damage the earth seriously. Asa matter of fact, there are some things we can do to cut down onenergy consumption and live a lifestyle of sustainability.
 To help protect the environment, experts suggest that we makechanges in our daily lives. For instance, we can go to nearbyplaces by bike rather than by car. Also, the environment will beclean if we eat natural foods that are free of chemicals. Simplepractices like the ones above are good for not only the earth butalso ourselves. When we ride bicycles, we are exercising ourbodies. Organic foods provide better nutrition for us. With ahealthy body, we will feel happy and thus enjoy good mentalhealty.
 Simple living creates a sustainable future that does not hurt theearth. It is a choice for us to live without many of the “extras” inour daily life. If we lead an eco-friendly lifestyle, we can make agreat difference to ourselves and the environment.
  
natural 自然的  produce 製造  damage 損害  cut down 削減
consumption 消耗  sustainability 維持性  environment 環境
expert 專家  rather than 而不是  chemical 化學的  organic 有機的
nutrition 營養  mental 心理的  human 人類  benefit 利益
42. What is the main idea of this passage?
(A) How a simple life can help humans and the earth.
(B) How humans can damage the environment.
(C) How to save our earth by reducing waste.
(D) How to reduce our living costs.