单词sucking reflex
un.: 吸吮反射网络: 吮乳反射；吸吮反射作用；吸吮反射动作
吸吮反射
It waves its hands, and every time it happens to touch its mouth, the mouth starts sucking by itself. It"s called the sucking reflex.
他会摆动两只手，每当手碰到嘴时，嘴就自己开始吸了，这叫吸吮反射。