Answer:
Hydraulic engineering is just a part of civil engineering. It is based on flow and conveyance of fluids, mainly water and sewage. It can be seen as an application of fluid mechanics for taking care of problems arising during storage, transport, regulation, measurement and use of water. This is needed while designing dams, canals, or cooling water facilities for thermal power plants.
On the medieval world-maps it was represented only the part of the world known as the 'old world', which is consisted of Europe, Asia and Africa. Before the big discoveries, people living in this continents had knowledge only of this part of the world, while South and North America, Australia and Antarctica where still unknown to them, thus they are missing in the world-maps of this period.
It really depends on which war the question is referring to, but if it's referring to WWII the answer would be true.
I believe the answer is <span>meridians</span>
