Which items originated in the Americas and became European staples as a result of the Columbian Exchange? corn, chocolate, rice, and sugar
rice, cattle, tomatoes, gold
wheat, chocolate, pineapples, potatoes
corn, potatoes, chocolate, tomatoes

Me with this psychology homework, i’m struggling with it.

How does danae feel about petraeus

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling