What is the author's main purpose

A．It is harder to track the precise effects of parental upbringing than the exact influence of the peer group in children.
B．Immigrant children tend to discard the way their parents speak quickly when they go to school.
C．It has been proved that peers have more impact on children's qualities such as to be honest or hard - working or generous.
D．It is easier for children to acquire a language at school than at home.

A．a way of collecting raw weather data
B．a forecast which can predict the weather conditions in the small area in an accurate way
C．a network to collect instant weather data
D．a more advanced system of weather observation