If your partner expresses unhappiness in your relationship, validate your partner's feelings and respond with self-disclosure.
C. used to produce other goods and services
The Columbian Exchange has brought new species to Europe. This includes new plant species, such as tomatoes and potatoes which have help combat hunger in Europe. This can be seen for example through the fact that when potato has a blight it caused the great famine in Ireland. However, the Columbian Exchange was not only positive for Europe as it also introduced sicknesses such as syphilis.
Nobody really knows who invented the iron foot Stirrup.
