Why does kevin breel use the words procrastination and procrastinate on in the excerpt instead of postponement and postpone?

Could someone me with this question?

Aman lives on the twelfth floor of an apartment building. every morning he takes the elevator down to the lobby and leaves the building. in the evening, he gets into the elevator, and, if there is someone else in the elevator -- or if it was raining that day -- he goes back to his floor directly. otherwise, he goes to the tenth floor and walks up two flights of stairs to his apartment.

Which development most aided explorers in their ability to set sail the oceans to discover the new world during the age discovery? a.waterproof sails b.the printing press c.map-making devices d.fictional travel accounts