What challenge did american farmers face in the late 1920s

Which of the following was the eventual result of the allied attempts to contain soviet expanion

"if i have seen farther than others," said newton, "it is because i have stood on the shoulders of giants." who were the giants to whom newton was referring? could this be said of any scientific accomplishment? explain.

Which country was the last to join the allied powers? o great britain o france o united states o china