boomer parents/American film rating system英文解释这两个词组

oomer parents：
Those parents who were born in the years with high rate of birth in the past,and within each family,there were lots of children.
American film rating system:
It is a typical American system designed for movies,whcih divides the movies into different level and standard marked with A,B,D and so on.

boomer parents--- the fathers and motherswho are members of the baby boom generation in the 1950s.
american film rating system----the system of classifying american movies according to quality or merit or amount .