Explain the following physical features and give an example of each :
a. Doab
b. Lagoon
a. Doab - The land that lies between two rivers is called doab. Eg. Agra
b. Lagoons - lagoons are salt water lakes separated from the main sea by sand bars and spits. Eg. Chilka Lake
Name any two products which are transported through a pipeline. Mention two advantages of this method of transport.