题目内容：

 

    Directions: Complete the following passage by using ONE word that best fits the context.

New studies show how food and its production affect the globe and its climate. The process of making a hamburger, for example, requires loss of energy. A cow has to be fed and raised on farmland. And cow waste is a major source of methane（沼氣）—  1.powerful greenhouse gas. The cow has to be killed. The meat has to be processed and shipped,   2.takes fuel. Most of the cow won’t even be used   3.meat people eat. By the time a hamburger finally lands onto a dinner plate, It has made bad effect   4.the environment.

We can reduce the production of global warming gases by eating less beef. Other kinds of meat like pork and chicken do  5.harm to the environment ---at least in terms of the amount of greenhouse gases released(釋放).However, all kinds of meat are harder on the planet   6.vegetables.  7.we’d change our diet to less meat and more vegetables, in fact it’s an environmentally friendly lifestyle and it’s beneficial  8.the environment.