class 7 Science Chapter 18 Wastewater Story
EXERCISE-1 Question 1: Fill in the blanks:(a) Cleaning of water is a process of removing _______.(b) Wastewater released by houses is called ________.(c) Dried _______ is used as manure.(d) Drains get blocked by ________ and ________.Answer: (a) Cleaning of water is a process of removing pollutants.(b) Wastewater released by houses is called sewage.(c) Dried sludge is used as manure.(d) Drains get …