Columbus left a few of his men behind with the natives and returned to Spain with many treasures and a few of the native Indians, as _____ that he had indeed reached Asia.
句意： 哥伦布留下了他的一些人和当地人一起， 带着许多珍宝和一些印第安人回到了西班牙， 以此证明他确实到了亚洲。 proof证明， 证据。 benefit利益； 好处。 regard尊敬； 关注。 profit利益， 利润。 由题意A正确。