A．smaller class brings lower achievements of the students
B．special attention encourages the students to do better in class
C．single sex is the only factor that influences the students' behaviors
D．single sex helps the students learn more in class

A．adult education has a short history of about two hundred years
B．in Chautauqua movement people called for rights on studying beyond formal education
C．in the early development phase of adult education, it was funded by the government
D．the Office of Vocational and Adult Education is not the only federal institute in supporting adult education

A．it is beneficial for girls and boys to study together
B．it is important to give girls equal opportunities to study
C．it is improper to mix boys and girls in classrooms
D．it is more convenient to manage single-sex schools