出国留学网托福频道为大家整理了托福考试相关资料，托福考试，托福听力，托福写作，托福预测等资料，出国留学网托福频道为大家提供了丰富的辅导资料，快来关注吧。
But in many cases consumers are misled if they believe organic foods can maintain health and provide better nutritional quality than conventionally grown foods. So there is real cause for concern if consumers, particularly those with limited incomes, distrust the regular food supply and buy only expensive organic foods instead.
The word "maintain" is closest in meaning to which of following?
(A) improve
(B) monitor
(C) preserve
(D) restore
正确答案：C
托福考试频道推荐阅读
