First learn basic HTML, then CSS and responsive CSS for Static websites and thereafter JavaScript and PHP for dynamic pages. If you also want to learn jQuery for more better works learn it at the same time with JavaScript
As we know that wave of sound is a mechanical wave and its speed is given by
v = (γRT/M)
whereas the wave of light is an electromagnetic wave and its speed is given by
c = (1/εoμo)
So speed of sound depends on temperature of air but speed of light doesn't.
The Rh factor(the Rhesus factor or Rh antigen), is a protein that can be found on the surface of red blood cells. It is one of the most important blood group systems in human blood typing. The presence or absence of the Rh factor is denoted as either Rh-positive (+) or Rh-negative (-).
The order of magnitude of a physical quantity is its magnitude in powers of ten when the physical quantity is expressed in powers of ten with one digit to the left of the decimal.
Orders of magnitude are generally used to make very approximate comparisons and reflect very large differences.
