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To call something “marginal” means it is not very good. Farmers have their own way to 47_____ marginal land: It is the last to be planted under good conditions, and has the 48_____ to be avoided under poor conditions. Low 49_____ soil is not the only reason land could be considered marginal. It might be in an area where rainfall is 50_____ or where a hillside might rise too steeply (陡峭地）.
There are uses for marginal land, however. Most often it is used as grassland. Grasses provide excellent 51_____ for grazing (吃草）animals like cattle, sheep and goats. Grass seed can be bought from a foreign supplier or 52_____ grasses can be used. However, using marginal land for grazing is not a simple issue. There is a 53_____ of overgrazing. Cattle can damage the crops by eating down to the roots. Also, the weight of the animals crushes the soil and can make it too hard for growing. A(n) 54_____ way to reduce the harm is to move animals from one field to another. This method is known as rotational grazing (循环放牧）which is extremely important for marginal land.
Another use for marginal land is for tree crops. Studies have 55 _____ that the white pine and loblolly pine (火炬松）are two kinds of trees that grow well on such land.
Failure to protect marginal lands can make a bad situation worse.But good planning can 56_____ a marginal resource into a highly productive one.
A）feed F) define K) native
B) priority G) adequate L) revealed
C) transplant H) transform M) prejudice
D) effective I) discouraging N) hazard
E) limited J) quality O) recovered
