Answer:
A smile. It's kinda hard not to blink.
Hitler's power was not checked when the US entered the war. The war with the US was between them and Japan. The USSR did join sides with the allies when Germany broke an treaty. However, the US did win the war between Japan.
I believe it was Sickness of FDR. He had polio so A should be the answer
I think the greatest reward is the knowledge that he or she has discharged the duty faithfully, honorably, and well!
Have a nice day,And good luck!!!