专家为各位考生整理了雅思词汇每日一题：unsubstantiated供考生们参考使用。
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.
The word “unsubstantiated” is closest in meaning to which of following?
(A) unbelievable
(B) uncontested
(C) unpopular
(D) unverified
