【正文】 that can happen with greater use of an agricultural system called mixes food crops with trees and perennial plants— those that return year after year. Soil scientist John Reganold says， “One of the major problems is that the soils are fairly poor in most of the how do you grow food crops on poor soils？There have to be food production systems that can build the soil and improve the yield.” says poor soil may have resulted from years of weathering that washed away many says some farmers may have done more harm than good. “They have been actually using farming practices where they’re not putting in anic ’re not putting in can ’t afford those it just runs the soil they’re worsening the situation.” The scientist says the word perenniation defines three systems that are already used in oldest of the three is called evergreen is where farmers plant trees with their in Africa have been doing this for sixty years， and it seems to be growing in popularity. The method is gaining widespread use in countries such as Niger， Burkina Faso，Malawi and trees are planted among maize(玉米 )， millet or shum not only add nitrogen(氮 ) to the soil through their roots， but also through their leaves when they fall off and break other times of the year， the trees can protect plants from strong sunlight. John Reganold says he knows of one woman who has had great success with perenniation. “She’s a grandmother in her name is Rhoda Mang’yana and she started using this system about twenty years her yields initially were about a ton of with a good year she gets four tons per hectare， four times what she was getting.” 56． The purpose of the passage is to________. A． tell people how to increase production B． introduce an agricultural system in Africa C． introduce the oldest farming method in Africa D． tell us how to prevent soil being poor 57． What does the underlined word “weathering” in Paragraph 4 most probably mean? A． Being exposed to wind and rain. B． Growing different crops. C． Being polluted severely. D． Being ploughed improperly. 58． According to the passage， which of the following statements is WRONG? A． Perenniation mixes food crops with trees and perennial plants. B． Poor soil is the main problem in increasing food production. C． Farmers may be more to blame for the present situation. D． American researchers first invented perenniation. 59． Evergreen agriculture is popular with the farmers mainly because it________. A． can build the soil and improve the yield B． can provide more wood as well C． is the easiest method to carry out D． is used for a long time B For years I wanted a flower garden， but with five children I was too busy to have was limited， and so was one of the children would want something that cost too much， and I would say， “Do you see a money tree outside ？ Money doesn’t grow on trees， you know.”Finally ， when all five had gotten through high school and college， and had started having their own families， I started thinking again about having a garden. However， I knew gardens cost after all these years I was used to living on a pretty lean， no173。 do not have a biological parent to test and reach a greater certainty， but given their ages and physical similarities， experts say it is likely they are fraternal twins. Douglas and Holly Funk hope to bring their Mia to Miami in sets of parents say they are mitted to staying in touch and often let the twins talk to each other on the phone. 64． Why did the girls’ mothers meet on the Inter? A． To pare photographs of the two girls. B． To find the girls’ biological kin. C． To test their suspicions. D． To enjoy the joy of adopting children. 65． Experts are still not 100 percent sure that the two girls are fraternal twins because________. A． DNA tests are still not accurate enough B． the two girls were born in two different families C． the DNA of a biological parent is still missing D． one girl was born a week later than the other 66． What Ramirez said in Paragraph 4 suggests that she________. A． didn’t believe what had happened B． was surprised at what had happened C． didn’t want to accept the fact D． was pleased with what they had done 67． What would be the best title for the passage? A． Adopted Twins Reunited After Online Chat B． Adopted Twins Live Happily in the US C． Suspicion Turned into Reality D． The Stories of Two Families D For the last couple of weeks， I