What were some of the ways civilians contributed to the war effort? Check all that apply. by conserving supplies
by supporting rationing
by knitting for soldiers
by collecting scrap metal
by serving in the US Army
by growing victory gardens
by issuing American war bonds.

One drawback of voluntary trade is that it a. requires two groups to use a common language b. can make one group dependent upon another for necessary goods c. doesn't occur unless there is a shortage of goods for at least one group d. forces groups to rely on themselves to produce all the goods they need