VOA慢速英语:语言学习能在睡眠中进行吗？

mammal – n. any animal in which the female gives birth to babies and feeds milk to its young

embed – v. set strongly into something

peak – n. the highest point of level

rhythm – n. regular movement of something

random – adj. done or chosen without any plan or system

conscious – adj. awake and aware of what is going on