Match the Column I with Column II .

a-4, b-3, c-2, d-1

The effort to cut down trees by the kings was thwarted by the Bishnois. A Bishnoi woman Amrita Devi showed exemplary courage by hugging a tree and daring king’s men to cut her first before cutting the tree. The tree mattered much more to her than her own life.

Ahmed Khan, aged 57 years old, has been producing plastic sacks for 20 years. About 8 years ago, he realised that plastic waste was a real problem. Polyblend, a fine powder of recycled modified plastic, was developed then by his company. This mixture is mixed with the bitumen that is used to lay roads.

There are several ways of removing particulate matter; the most widely used of which is the electrostatic precipitator , which can remove over 99 per cent particulate matter present in the exhaust from a thermal power plant.

A scrubber  can remove gases like sulphur dioxide. In a scrubber, the exhaust is passed through a spray of water or lime.