When researching a topic, why must you be on guard against bias?

What is articulating thoughts and ideas effectively using oral written and non verbal skills a part of

Who is the speaker in this excerpt from book 13 of homer’s odyssey, and what inference can you make from the tone?

The persian wars started when emperor darius i began an invasion of greece. what caused darius to decide to attack greece? a. greek pirates had raided persia's merchant ships and coastal towns. b. greek armies had attacked and taken over land that belonged to persia. c. greek city-states had supported rebellions in the persian empire. d. greek leaders had declared independence from the persian empire.