At 4:30 am on April 12, 1861, the artillery of the Army of the Southern Confederate States fired the first shots at Fort Sumter, beginning the direct attack on this fortified Union position and the American Civil War.
They use scientific methods such as radiocarbon dating
They make an assumption. They compare it to other historical sources
The correct answer is Social Security. It does not however only provide
income but numerous things such as medical insurance and any things that
old age might be the cause of. Since people would not want to hire old
people or take care about them, the social security act would take care
for them.
I think theres 2 that you could argue.
Revelation 22:6
[6] And he said unto me, These sayings are faithful and true: and the Lord God of the holy prophets sent his angel to shew unto his servants the things which must shortly be done.
This says that the prophesies are true and God has sent his angle to prepare for them to come true.
Revelation 22:16
[16] I Jesus have sent mine angel to testify unto you these things in the churches. I am the root and the offspring of David, and the bright and morning star.
This again says that Jesus has sent an angel to prepare the world for the prophesies.