During the 1840s and 1850s, larger numbers of immigrants came from all of these countries except
a. russia, because people were fleeing the communist revolution
b. ireland, because people were fleeing the irish potato famine
c. china, because people were fleeing the taiping rebellion
d. all of the answers are correct.

In e. c. tolman's experiment, some rats were trained to run through mazes for standard food goals, while other rats were allowed to explore the mazes for 10 days without food goals or other rewards. later, when food rewards were placed in a box at the far end of the maze, the previously unrewarded rats reached the food box as quickly as the rewarded rats after only one or two trials. this experiment demonstrated that the rats had the ability to form of their surroundings.