题目

Why does eating raw foods or whole foods become more and more popular nowadays? One reason is that eating these types of food reduces the risk of acid accumulation in your body. Raw and whole foods are usually digested more efficiently than cooked and refined foods. When we cook foods, we destroy the natural enzymes(酶)that are part of the food in its raw form. These enzymes were intended by nature to help us digest the food. When we consume food without these natural enzymes, our bodies either digest the food improperly or allow too many nutrients to be absorbed into the bloodstream. 生长期间的马铃薯，当块茎的一部分露出地面时，不几天就变成绿色，这是由于（??） ????A．生物体都有应激性??????B．马铃薯对温度的适应 ????C．茎细胞中白色体变成叶绿体??D．发生可遗传的变异