sucking response

例句：

1. 1. When she was young, she would often suck on her thumb during sleep.
   她小时候睡觉时经常吮拇指。
2. 2.The baby's sucking reflex is a sign of hunger.
   婴儿的吮吸反射是饥饿的标志。
3. 3. During the first few weeks of life, babies need to suck on their mother's breasts for nutrition.
   婴儿在出生后的前几周需要吮吸母亲的乳房来获取营养。