英语时差：怎样能让宝宝睡着？（上）

Parents of young infants know just how rare and valuable uninterrupted sleep can be. As it turns out, the timing of breast milk production may help play a role in facilitating sleeping in an infant. Some mothers express breast milk during the day and save it for bottle-feeding their infants at night. This strategy allows fathers or other carers to help with the night-time feedings, and can make late night feeding quicker and easier for the mothers. However, the plan may actually result in a more sleepless night for infants and their parents. It turns out that not all breast milk is the same. Breast milk is composed, in part, of compounds called nucleotides--the building blocks of DNA. Breast milk contains many types of nucleotides, thought to be important for tissue development in growing infants.