Answer:
A triangulation station, also known as a triangulation pillar, trigonometrical station, trigonometrical point, trig station, trig beacon, or trig point, and sometimes informally as a trig, is a fixed surveying station, used in geodetic surveying and other surveying projects in its vicinity.
~Hoped this helped~
Answer:

The unit of electric current that is equal to the flow of one Coulomb per second.
Ampere or ‘amp’ is a unit of electric current denoted by A. It is named after the French Physicist and Mathematician Andre-Marie Ampere, who is considered as the ‘Father of Electrodynamics’.
Answer:
Cyclones and ocean currents transport heat towards the poles
Explanation:
The reason why the tropics is not getting hotter and the poles not getting colder is due to the activities of cyclones and ocean currents which transport heats towards the poles thus enabling the temperatures at the tropics and the poles to remain fairly constant.
By observing how seismic waves are absorbed and refracted, scientist have been able to work out where the properties of the earth change dramatically. our understanding of the internal structures of the earth and the size of its core is based on these observations.
basically:
size of core
structure of the earth I.e. the layers of the earth
and I think the last one is how the internal structure is changing? not sure on the last one but its still a solid guess.
What? im unable to get the Question so if you can tell in detail i may answer