The opinions and prejudice of an author in writing.
I believe that those two elements greatly affect bias in history because we can never be 100% sure of everything that (may have) happened in history (especially farther in the past), so opinion can affect a historian's writings. Also, everyone is prone to some sort of prejudice, so this can also affect history.
Depaboek äioenhdis upend kshskom khśjdksbk jeipbfjs
Energy nurence and viamins ar the thigs that cone frome it