五、综合阅读（20分）A Zheng He was a famous Chinese explorer. In 1405, he set off from China on the first of seven great （A） . This was （B）nearly a century before Christopher Columbus first set sail on his journey of discovery to America. His travels were so important that they are still studied today. Zheng He （C）在1731年时出生于云南. He rose to become a trusted official of the Yongle Emperor of the Ming Dynasty. The emperor ordered Zheng He to visit and explore the lands outside China. His task w
