You can't eat four parts of crab: crab cheeks, crab heart, crab stomach and crab intestines. Crab gills are two rows of gray fan-shaped soft tissues on the crab after the crab shell is opened. These two rows of "small fans" are crab gills. Crab gills are the respiratory system of crabs and should not be eaten.

Common sense of life refers to the scientific knowledge summarized by people in their daily lives, which can be divided into common sense contents of physics, biology, chemistry, medicine, first aid knowledge, geography, safety, cosmic celestial bodies, natural phenomena and so on.