चारों भाषा कौशलों में से कौन सा युग्म सुदृढ़ीकरण कौशल (reinforcement skills) का गठन करता है?

The development of reading and writing skills:

'Listening and speaking are primary skills, while reading and writing are secondary skills.' This statement refers to which principle?

Asking a student to read a poem primarily aims to test which skill?