A．The wealthy white children.
B．Children from middle class families.
C．Poor white children.
D．Poor children from ethnic minorities.

A．Since the kindergarten.
B．Since the primary school.
C．Since the middle school.
D．Since the high school.

A．Improvements of children's achievements in school can be made.
B．Children's heath can be improved.
C．The school needs to care more about children's special talents.
D．The educational system can be improved.