Questions

Drowsiness is the state of feeling sleepyness and tired in the day time. It affects our senses especially the sense of vision.

Benjamin Franklin has long been credited with the invention of bifocal lenses and he was the first to wear bifocal lenses. He did not produce them himself but instead had some optician in London or France make them for him to overcome Presbyopia, a condition that Franklin suffered. He was tired switching between lenses for far and near sightedness. And that resulted in inventing Bifocal Lenses.

The main use of salt in the diet is to produce in small amounts the hydrochloric acid required for the digestion of food.

Nixon

The ozone layer is a region of Earth's Stratosphere that absorbs most of the Sun's ultraviolet (UV) radiation. It contains high concentrations of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

The Atmosphere is divided into 4 layers according to major changes in temperature. They are :

1. Troposphere,

2. Stratosphere,

3. Mesosphere  and

4. Thermosphere.

The farther away from earth, the thinner the atmosphere gets.