classes:  lecturer. I studied at an English center outside of school, the duration is reasonable, not much less about 2 - 3 periods a session!  curriculum. I studied at an English center outside of school, the duration is reasonable, not much less about 2 - 3 periods a session!  facility. I studied at an English center outside of school, the duration is reasonable, not much less about 2 - 3 periods a session!  general. I studied at an English center outside of school, the duration is reasonable, not much less about 2 - 3 periods a session!