Teachers need to be awake and prepared to manage learning to prepare students with skills for living in the world in the 21 century, which changed from the 19 and 20 of the 21st century.
Teachers need to be alert and prepared to manage learning to prepare students with the skills for living in the world in the 21th century to the 20th century and 19.
The teacher must be alert and prepared in learning to prepare students to have the skill for living in the world in the 21st century out 21 changed from the 20, and 19.