Through spectral analysis of Yangshao culture pigments, the most prominent element in the red pigment was _____. A: tin B: silicon C: copper D: iron

Which of the following is not the characteristic of pigment epithelial cells. A: Derived from neuroectoderm B: Contains a lot of melanin particles C: Phagocytic function D: Storages vitamin A E: Can synthesize visual pigment

which of following do not belong to pathogenic variations of the endogenous genes ( ) A: gene amplification B: abnormal gene expression C: invasion of the foreign genes D: gene arrangement E: point mutation

Which nutrient is not an important source of fresh vegetables and fruits? A: Vitamin C B: Carotene C: Riboflavin D: Proteins

According to the instructor, what characteristic should a pigment have A: Ability to be applied at any temperature B: Ability to dry quickly after application C: No loss of strength when dissolved D: No harmful reaction with other pigments