Concept:Active involvement helps students construct knowledge and connect their everyday experiences with classroom learning.
Explanation:When children bring items from home, they begin learning even before the experiment starts.
They observe and identify each material, which builds curiosity and understanding.
This hands-on process allows students to construct knowledge easily and comfortably.
Their own familiar objects help them relate local knowledge to school knowledge, making learning authentic.
Involving families or saving school materials is not the main reason here.
Thus, reasons C and D are correct.
Answer:Option A (C and D only)