Colour additives belong to one of two groups: pigments derived from natural sources such as vegetables, minerals or animals and those not found in nature and must be man-made.
Vegetarians fall into groups defined by the types of animal-derived foods they eat.
根据素食者对源自动物的食物的态度,他们可划分成如下几类。
3
The present paper discussed some possible translational types in detail, and derived the elements of the pseudo-symmetry for the low symmetry crystal systems (74 space groups).