A primary source is from someone who was apart of the event that’s being sourced, such as a holocaust survivor recounting the events of the holocaust, or someone who witnessed a murder. A secondary source would be someone sharing the primary source, such as a newspaper or a book! Hope this helps!
Ore and more protection/defense system
"<span>An override needs a three-fourths vote" would be the best option from the list as long as your'e referring to an override of a presidential "veto," since this indeed requires such a fraction. </span>