What is the common main idea in "a continent of ice"

silk

indigo  

rice

all the other answers are wrong

because its important to learn about other countries and how high tech they are compared to us. also its good to learn about other cultures and how ours differs and in common also we need to learn about companies that we still buy since they ship it here.

a u.s. citizen has to have lived in and been an american citizen for a year or more be for he or she can vote for presidential or country wide elections. they also have to register to vote. if the voting is for state representatives or issues, they have to have lived in that state for one month or more and meet the requirements for country wide elections.