Answer: d obviously cause it has created more dispute
Explanation:
Telescope
Thermometer
Air pump
submarine
Most caste systems in our history were based on a person's skin color. I'm gonna take a guess that it would be the same for this part of the world.
This would be Majority Leader.
Hope this helps!
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Answer in BOLD
Most military people I have known believe the US Air Force is the safest branch to be in from a combat perspective. In the Army and Marines, the enlisted men do the vast majority of fighting, and, therefore, getting killed.