Which topic would be most appropriate for a four- to five-page research paper? are boys and girls different? do children learn better in boys-only and girls-only schools? how many boys-only schools are in the us? are male teachers or female teachers more effective?

I think it would be interesting to talk about:  Are male teachers or female teachers more effective?

Because it would give a gender perspective to an activity that is always related to women, taking into account their old role as caregivers.

Apart from the foregoing we see that in the definition of teacher or teacher make reference to the person who has studied teaching and is responsible for teaching students, whether children, primary or secondary, among others, in schools, schools or universities. Some teachers may be assigned in secondary education institutes in social guarantee programs, compensatory education or support for students with special educational needs, as well as in adult education centers. This definition does not make explicit reference to the gender that must have been selected, nor of the benefits or negeative aspects of the same.

it required the unanimous approval of the states before the congress could enact any measure.