Have all the continents been visited by the participants of the first round-the-world expedition? Which continents were unknown at that time?

No, mariners did not visit North America, Antarctica and Australia. At that time, Australia and Antarctica were not known.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.