The Taj Mahal is an example of Mughal architecture
Answer:
The first occurrence (chronologically) was
Regional kingdoms began to replace most of the city-states of the northern region of Harappan Society.
Explanation:
Of all that are stated in the question, Regional kingdoms began to replace most of the city-states of the northern region of Harappan Society first occured
Around 4,350 years ago, many factors responsible for migration led people to abandon their settlements and migrate to southern and eastern regions of India, according to a study by Indian Institute of Technology Kharagpur.
This is also known as Indus valley civilization
Rock composition and measuring the seismic waves provide knowledge for the scientists to study the interior of the earth.
Explanation:
When the crust gets distributed it is easy to study the layers of the different materials that got settled and compacted in the earth. Patterns that are formed in the rocks provides to be a good source to know about the earth's crust. rock cores are cylindrical sections which are cut and removed from the earth crust for research purposes.
It is impossible to drill to the center of the earth and so scientists rely on seismic waves and the speed of the seismic waves depends on the material on which it is passing through. The toughness and stiffness obstruct the speed of the waves which is a means for the scientists to undertake research on the substance which hampered the speed of the seismic waves. P-waves, or pressure waves, which go through both liquids and solids, and S-waves, or shear waves which go through solids but not liquids. This provides the best data to undertake research regarding the earth' crust by the scientists.