Why fighting stretched turn into long years of trench war face during ww1

Which statement best describes the underground railroad? a.) it is a train that took slaves from the south to the north. b.) it is a business that harriet tubman founded to slaves become free. c.) it is a secret route that slaves took to escape from southern slave states to the north. d.) it is a road that slave owners disliked using for travel.

Ineed to have answers for numbers 2-4 reply to this question

What was gained through the gadsden purchase