OG5 阅读 Q23

Choice B is the best answer. The passage clearly states that conventional agriculture is very efficient, especially when compared to organic farming: "organic farming yields 25% fewer crops on average than conventional agriculture" (lines 40-42,"and ...to") and in a study "organic farming delivered a lower yield for every crop type" (lines 51-52, "legumes...disparity"). It can therefore be understood from the passage that conventional agriculture does a good job maximizing the output of the land that is farmed. 
Choice A is incorrect because the passage states how efficient conventional agriculture is in regard to the amount of food it can produce but does not indicate that it produces a significantly wide variety of fruits and vegetables. Choice C is incorrect because even if the passage does say that each American farmer can produce crops to feed "over 155 people worldwide" (lines 16-17,"each...and"), it never claims that conventional agriculture can satisfactorily feed everyone in the world. Choice D is incorrect because the passage states that conventional agriculture uses a great deal of nitrogen, not that it changes the need for nitrogen in plant growth one way or the other.