Iwas a portuguese nobleman who left portugal in 1497, sailed around africa, and reached india in may 1498. who was i?

Which would make the best heading for this list of notes about the migration of african-americans during the reconstruction era?

Why might it be important to know a currency’s exchange rate

"if i have seen farther than others," said newton, "it is because i have stood on the shoulders of giants." who were the giants to whom newton was referring? could this be said of any scientific accomplishment? explain.