At first, this compound containing Tetra Ethyl Lead was used in automobiles. ​

It was later learned that burning of the fluid caused many health problems like high blood pressure.​​

Name the substance that caused these hazards.​

The earliest wheel constructed to utilise the wind was the wind wheel of Greek engineer Heron of Alexandria in 1st century A.D. ​

In ancient China and Tibet, a prayer wheel also harnessed the wind. ​​

What are these giant wheels known as in the modern world?​​

India is known for being notoriously polluted having         14 cities out of the top 20 most polluted city across the world.​​

This type of pollution causes diseases such as Ischaemic heart disease, Stroke, Chronic obstructive pulmonary disease among others. ​​

There is a considerable rise in this pollution throughout as almost 50% of the worlds population now live in cities.​​

What type of pollution are we talking about?​​

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One of the significant impacts of air pollution is this kind of rain which is acidic in nature due to mixing of normal rain water with air pollutants such as sulphur dioxide which causes damage to forests and rivers.​

What is this kind of rain called?

Mauna Loa and Kilauea volcanoes on Hawaii’s big island erupt and add acres of land each year to the island.​

Such formations of rocks, soil naturally or even when upper layer of soil is deposited to a new place by wind or air is called as Deposition.​

What is the process called when the same soil and rocks are moved away by air and water?

Aditya, is India’s first ________ powered ferry operating in Kerala. ​

This boat is been operating since its launch on 12th January 2017. ​

On its two years service the boat carried 600,000 passengers and travelled a distance of 38,000 km without a single drop of fuel thereby saving 58,000 liters of diesel. ​

The boat is powered with what energy?