I. Infants are easily frightened during the neonatal period or within 3 months of age, cry more than once or cry faintly, and have difficulty sleeping. Difficulty in feeding, manifested as weakness in breastfeeding, refusal of milk or crying while eating, swallowing and chewing, choking and coughing while eating. Third, when hearing noise and position change, they are prone to hug-like fright and cry. 4. 4-6 week old infants reflect poorly on external stimuli and have indifferent expressions. V. At 3 months of age, infants stand with their legs straight when they are supported in the axillary position; they cannot raise their heads in the prone position. Sixth, at 4-5 months of age, the baby still has an unstable vertical head, cannot follow objects, still shows inward thumb and hand clenching fist; cannot reach out to grasp objects. At 4 months after birth, the body is flabby and cannot keep itself in a certain position; it cannot roll over, and the spontaneous movement is reduced or the movement is abnormal, such as prematurely turning over suddenly with the whole body in a rolling pattern; the limbs are stiff. Seven, 6-8 months still can not sit alone. After 8 months of age, there is still no crawling awareness and movement.