https://learnenglish.britishcouncil.org/vocabulary/b1-b2-voc 

https://yosoytuprofe.20minutos.es/2018/09/19/100-problemas-de-ecuaciones-de-primer-grado-resueltos/ 

exámenes B! 

 

https://englishfile4e.oxfordonlinepractice.com/app/dashboard 

https://www.youtube.com/watch?v=CPG1fr-bfB0 

https://www.youtube.com/watch?v=QEMoROXozSM