【英语时差8,16】玉米大豆种植模式效益更好？2

 These bacteria split the nitrogen atoms apart and combine them with other molecules¹, making the nitrogen available to the plants that the bacteria are living on. In exchange, sugars produced by the plant’s photosynthesis² fuel the process of nitrogen-fixation and enable the bacteria to grow. These bacteria not only help the plants they live on, but release useable nitrogen into the soil which is taken up by other plants, and in turn passed on to animals that eat those plants. The Maya knew that corn and beans grow well together, just as in this country some farmers rotate their crops, planting alfalfa or beans every few years to replenish³ the soil’s nitrogen.

1 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

2 photosynthesis   

n.光合作用

参考例句：

• In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几乎只发生在叶内。
• Chloroplasts are the structures in which photosynthesis happens.叶绿体就是光合作用发生的地方。

3 replenish   

vt.补充；(把…)装满；(再)填满

参考例句：

• I always replenish my food supply before it is depleted.我总是在我的食物吃完之前加以补充。
• We have to import an extra 4 million tons of wheat to replenish our reserves.我们不得不额外进口四百万吨小麦以补充我们的储备。