题目

Tens of thousands of ancient pictures carved into the rocks at one of France’s most important tourist sites are being gradually destroyed. Scientists and researchers fear that the 36,000 drawings on rocks in Mont Bego in the French Alps are being damaged so rapidly that they will not survive for future generations. The mountain, believed to have once been a site for prayer, is scattered (散布) with 4,000-year-old drawings cut into bare rock. They include pictures of cows with horns, cultivated fields (耕地) and various gods and goddesses. But as the popularity of the site increase19．人们把食物分成绿色食品、蓝色食品、白色食品等，绿色植物通过光合作用转化的食物叫绿色食品，海洋提供的食品叫蓝色食品，通过微生物发酵制得的食品叫白色食品．下面属于白色食品的是（　　）A．食醋B．面粉C．海带D．菜油