Which of the following things were the Americas sending to Europe during the time of the Columbian Exchange

The Americas brought gold, silver, rice, potatoes, pineapples, strawberries, tobacco, beans, vanilla, chocolate and syphilis to Europe. Africa has also imported slaves to America.

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".