The chariot was first used as a weapon by the
egyptians
persians
hittites
greeks

The Hittites were the first people to use the chariot as weapon of war.

The chariot was a light vehicle on two wheels that was drawn by one or more horses. It usually carried  two standing persons, a driver and a fighter who used bow and arrow or javelins.

The Hittites managed to win many battles due to the use of their light chariots. In addition to being light weight, their chariots were fast and narrow enough to fit into small paths and roads. 

an earnest tone.

because portia wants to know why brutus has been acting strange lately.