Answer:
Why did Europeans want to explore other lands?
They wanted to explore other lands because European nations were interested in finding new lands to trade with, or to establish new colonies from where to extract resources.
How did Portugal gain an advantage in trading in comparison to other European nations?
Because it had a favorable geographic position, in the southwestern most point of the European peninsula, facing the Atlantic Ocean. Portuguese explorers were the first to navigate around Africa, Asia, and to establish their own colonial trade ports in these continents.
How did Russia's expansion differ from that of other European nations?
Russia had very little access to the Atlantic Ocean, so it instead expanded eastward, conquering and colonizing Siberia. It also expanded northwards, establishing small cities in the Artic coast.