【单选题】
Cape Verde (佛得角) is an Africa country that is made up of 10 main islands and 5 tiny ones. It lies in the Atlantic Ocean, about 400 miles west of Senegal on the African mainland.
Cape Verde has a population of about 329,000 and a total area of 1,557 square miles. Sao Tiago, the largest island, covers 383 square miles. There are no people living on Santa Luzia, the least of the ten larger islands, nor on the five small islands. Praia, the capital of Cape Verde, is on Sao Tiago. However, the largest city, Mindelo, is on Sao Vicente, the sixth largest island of the group. Portugal (葡萄牙) ruled the islands from the 1460’s until 1975, when Cape Verde became independent. Now Cape Verde is a republic with an elected president. About 70 percent of the people of Cape Verde have mixed black African and Portuguese (葡萄牙的) blood. The rest of the population are mostly black Africans.
Five hundred years ago Cape Verde was ______ .