"A pair of scissors consists of two pivoted blades. In lower-quality scissors, the cutting edges are not particularly sharp; it is primarily the shearing<span> action between the two blades that cuts the material. In high-quality scissors, the blades can be both extremely sharp, and tension sprung - to increase the cutting and shearing tension only at the exact point where the blades meet. The hand movement (pushing with the thumb, pulling with the fingers) can add to this tension. An ideal example is in high-quality tailor's scissors or shears, which need to be able to perfectly cut (and not simply tear apart) delicate clothes such as chiffon and silk."</span>
Volcanic eruptions and/or earthquakes caused by the shifting of tectonic plates
Water cycle is effected by pollution, whether it is water pollution or air pollution. Air is polluted by Suspended Particulate Matter and by different harmful gases like Sulphur dioxide etc. These gases react with water vapours in the sky, making the water in the clouds acidic. This acid falls as rain water causing acid rains. This acid falls in ponds, on land, in fields, causing harm to us and to the crops as well as to the fishes or creatures in water. When the water evaporates from ponds, rivers and oceans to make water vapour, the the water in these water bodies becomes more acidic, and again when acid rains occur, this acid again mixes with the water of the water bodies, which already has acid, causing the water to become more concentrated.
The sequence is in the following order;
- The sun radiated sunlight (visible) photons
- Photons from the sun strike the earth and become infrared photons
- Earth radiates infrared photons into the atmosphere
- CO2 in the atmosphere absorb infrared photons
- CO2 in the atmosphere emit infrared photons back towards earth
