Throughout history there (has, have) been many legends about the Milky Way.

Have

Explanation:

answer: it is true that students often work and do household chores, but managing homework in addition to other responsibilities students learn to organize their time efficiently and prioritize their studies.

the first argument attacks those who disagree, asking them to be "realistic" and "accept facts." this is not conducive to healthy debate and disagreement. the second one only takes into account a section of the student population, and ignores the other one. finally, the third option offers only anecdotal evidence. it is only the last option that provides a well-constructed argument in a persuasive way.