A．slowB．noisyC．suddenD．jumpyThe train came to an abrupt……

单项选择题Babies can learn language even in their sleep.

单项选择题An infant can recognize a lot of vowels by the time he or she is a year old.

单项选择题Finnish vowels are easy to distinguish.

单项选择题The three vowels mentioned in this article are all Finnish sounds.

单项选择题The study shows that the infant’s cerebral cortex is working while he is asleep.