(1) Trachea or windpipe has rings of cartilage (it splits into the left and right lungs). (2) The epiglottis covers the larynx (the food does not enter the windpipe while eating).

CORONA-19 is a respiratory disease as it mainly affects the lungs. It is transmitted from an infected person mostly by respiratory droplets released into the air when an infected person sneezes or coughs directly without covering his mouth or nose. ...

We will find fine microscopic sulphur particles precipitating in about 2 and 3 minutes due to the reaction between sulphuric acid sodium thiosulphate.

Out of the given four materials the refractive index of glycerine is highest. So, greatest deviation of incident light ray is observed in case of glycerine.

As MnO₂ reacts with HCl to form salt, water and chlorine gas, it is basic oxide since it reacts with an acid. Moreover, oxides of metal are basic in nature whereas oxides of non-metals are acidic in nature.