Why this invention is created interchangeable parts

Which of the following statements about this graph is accurate? world grain production has increased in every year since 1950. the amount of grain grown between 1950 and 1980 decreased. world grain production has generally increased between 1950 and 2010. more grain was grown in 1950 than in any other year.

After world war one, how did the allied countries hope to keep germany from becoming too powerful again?

Kennedy singles out one group of countries that the united states will defend against any attacker what countries are they