语法与词汇 There are numerous unsubstantiated reports that natural vitamins are superior to synthetic ones, that fertilized eggs are nutritionally superior to unfertilized eggs, that untreated grains are better than fumigated grains, and the like.
【正确答案】 D
【答案解析】句意：有许多未经证实的报道称天然维他命比合成的要好，还声称毛鸡蛋更富含营养、粗谷比精谷好等等，这些都未证实过。unsubstantiated未经证实的，无事实根据的。unverified未经核对的，未经证实的。两者意思相近。unbelievable难以置信的。uncontested无竞争的；无异议的。