Drains get blocked by_________and__________.

The process of wastewater treatment is commonly known as

Who said this ("no one need to wait for anyone else to adopt a humane and enlightened course of action.")

Micro-organism which causes cholera.

In the year_________ the Government of India has initiated a new mission known as (swachh Bharat)

Clean water is used for

A word related to hygiene

Which of these statements are correct about ozone