Translation of por qué

This behavior is totally normal for this kind of traffic volume. To increase efficiency they could increase the gateway to five. Once you send the traffic, I will ask my boss to test it on both.
It comes not only from the need to feel superior (which would be a legitimate and natural desire), it is also the consequence of ignorance, believe in stereotypes and old-fashioned intolerance.
The travel agent's representative promised that they would return us the difference of the money. They also assured us that we would get special treatment, such as extra drinks and a Kayak expedition.