A. One system of curriculum, medium of instruction and assessment in a state
B. Involving teaching staff to develop new relevant curricula
C. The key concepts over time in the context of new
D. Focuses on what learners are excepted to know in various subject areas
Explanation
The Spiral Curriculum is an educational concept that focuses on revisiting key concepts over time in the context of new learning experiences.
It emphasizes the iterative process of learning, where students encounter fundamental ideas multiple times throughout their education, each time building upon their previous understanding in a deeper and more complex way.