Researchers tracked 500 children in a country and found that the fastest-growing period of the human brain was within three months after birth, and the brain could reach more than half the size of an adult. The answers to the following ______ items best evaluate the correctness of the above conclusions. ["Do any of the 500 children's brains grow rapidly after three months of birth?", 'Are there follow-up studies of children in other countries.', "Are children's brain functions the same as adults?", "Are boys 'and girls' brains growing at the same rate?"]