Just like fingerprints, each person’s DNA is unless he has a twin．
A. unusual
B. normal
C. various
D. unique
网友回答
A. unusual
B. normal
C. various
(答案→)D. unique
解析：词义辨析. Unusual不同寻常的;normal普通的,一般的;various各种各样的;unique独特的,稀罕的.句意:就像指纹一样,每个人的DNA都是独特的,除非他有一个孪生兄妹.故选D.