A、 They become more mature in a shorter time.
B、 They might be of different genes from their ancestors.
C、 They are much more nutritious with better taste.
D、 They might take a totally different look than before.

【正确答案】 B

【答案解析】解析：短文开篇即介绍现在的西红柿未必是以前人们所食用的西红柿。而很可能是实验室的转基因产品；接着说市面上许多蔬菜水果的情况也是如此。B是对原文change the genes of plants的同义改写，故选B。

A、 Which food could be sold.
B、 How foods must be described.
C、 When certain foods are available.
D、 What nutrients food should contain.

【正确答案】 B

【答案解析】解析：短文提到，“美国的FDA组织的职责是规定上市出售的食品的描述事宜”。故选B。

A、 They have trouble in moving.
B、 They have trouble in speaking.
C、 They have trouble in sleeping.
D、 They have trouble in breathing.

【正确答案】 D

【答案解析】解析：短文提到，食品描述的好处之一在于提醒顾客注意在食用后可能带来的不良及应，如皮肤红疹、呼吸困难、反胃等。故选D。