【英语时差8,16】玉米大豆种植模式效益更好？

 For thousands of years, the Maya, in what is now Central America, have planted their fields with alternating rows of corn and beans. Together corn and beans provide all the protein needed for a human diet. But that’s not the only reason this combination has been so successful. If you pull up a bean plant you can see that the roots are covered with little, reddish nodules. Bacteria on the roots of the plant trigger the plant to produce these nodules, which provide a home for the bacteria. These “nitrogen-fixing bacteria,” as they’re called, live only on the roots of legumes, such as beans and alfalfa, and provide virtually all the nitrogen used by plants and animals. The atmosphere is about seventy-eight percent nitrogen — an essential element for most forms of life. But atmospheric¹ nitrogen consists of pairs of nitrogen atoms bonded² so tightly to each other that they can’t be used by either plants or animals. And that’s where nitrogen-fixing bacteria come in.

1 atmospheric   

adj.大气的，空气的；大气层的；大气所引起的

参考例句：

• Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
• Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。

2 bonded   

n.有担保的，保税的，粘合的

参考例句：

• The whisky was taken to bonded warehouses at Port Dundee.威士忌酒已送到邓迪港的保稅仓库。
• This adhesive must be applied to both surfaces which are to be bonded together.要粘接的两个面都必须涂上这种黏合剂。