How BS emission standards changed over time? Why is it essential?

What is tuning of radio or T.V.circuits? Why it is essential?

Explain the process of charging of tRNA. Why is it essential in translation?

Explain the process of sewage water treatment before it can be discharged into natural bodies. Why this treatment is essential?

How will you classify man as carnivore or omnivore? Why?

i. Will the velocity of a stone thrown vertically upwards remian constant or will it change with time? How will it change? ii. Why doesn't the stone move up all the time? Why does it fall down after reaching a certain height? iii. What does its maximum height depend on?

In a road accident, Moses fractured his leg. One of the passer by, tied a wooden plank to the fractured leg while Moses was rushed to the hospital was this essential? Why?

Montreal protocol is an essential step. Why is it so?

Why a reproduction is an essential process ?

We have read about how Indian scientist won the battle for patent of Turmeric and Basmati rice. Why was opposing these patents essential?

Will the velocity of a stone thrown vertically upwards remain constant or will it change with time?How will it change ?