Question

Give scientific reasons.
(a) We must use cotton clothes in summer.
(b) We must observe economy in the use of materials.
(c) Saving paper is the need of the hour.
(d) Man-made materials have more demand.
(e) Humus is a natural material.

Answer 1

The scientific reason for why should we cotton clothes in summer is that we have a tendency of sweating much and cotton fabric soaks up this sweat and is of help to the body in cooling down.

The importance of observing economy in the use of materials is the reduction of costs could be of benefit to the environment. An example is a lower-priced recycled material.

Saving paper is the need of the hour as it takes approximately seventeen fully developed trees for manufacturing a tonne of paper and we all know that trees are vital for maintaining a poise of nature.

There’re several reasons why Man-made materials have more demand. One is that while the fields made use of for manufacturing cotton or wool must contend with areas made use of for growing food. Moreover, the manufacture of natural fibers is mostly associated with the weather. In contrast, organic raw materials made use of in synthetic fibers are going to be available on a nearly limitless basis for several decades to come and they are also significantly less costly. Man made fibers can also be adapted for meeting various applications and are able to be endowed with diverse characteristics.

Humus is a natural material as it’s the chunky brown or black colored substance that stays behind after the decomposition of a good part of organic litter. Humus consists of numerous helpful nutrients for healthy soil. 

Answer 2

We should wear cotton clothes in summer because during summers we tend to sweat a lot and cotton fabric absorbs this sweat and helps the body to cool down. ... Cotton allows better air circulation, which helps in absorbing and removing body moisture caused by sweat.

Our use of materials is very large and increasing with population and economic growth. Energy and water use accompany materials use. Our use of materials now challenges the capacity of the Earth – air, water and land – to withstand the many resulting environmental problems.

Paper should be saved because it takes around seventeen full grown trees to make one tonne of paper. Trees, as we know, are important to maintain a balance of nature. Therefore,' in order to save trees and prevent the impact of their loss on living organisms, we need to save paper. ... Collect used paper and recycle it.

Maintaining man-made materials requires less care and attention than natural materials. Man-made materials are readily available because they are cheap, durable and hardy -- they can be subjected to rougher handling than natural materials and resist breaking and damage.

Humus is dark, organic material that forms in soil when plant and animal matter decays. When plants drop leaves, twigs, and other material to the ground, it piles up. ... Many of these chemicals are important nutrients for the soil and organisms that depend on soil for life, such as plants.