(a) How can unclean or dirty water harm our body? (b) Have you ever got dirty or unclean water in your area? What was the reason for this? (c) Do you know anyone who has fallen sick because of such ...

In Class 4th, students are required to grab all the fundamentals of a subject so that they do not have to face any problem while studying that subject in higher classes. Here, NCERT books play the ...