coerciveness
Compulsory education is indispensable for every child, just like sunshine and air every day. This is compulsory, and every child must receive education.
universality
Compulsory education does not distinguish between you and me, rich and poor, and everyone has the right to enjoy education. It is universal that every child should have the opportunity to receive education.
Free sex
Compulsory education is free, the state pays the bill, and we benefit. Every child has the right to receive free education regardless of economic conditions.