【正确答案】 B

【答案解析】The European taste for spice began to revive in the 9th century. At that time, the Arabs cut Europe off from the spice islands. They became the masters of the spice trade and kept the sources of spices secret from the Europeans, thus made spices enormously expensive until Marco Polo traveled to China on the Silk Road. He described hot lands where he saw spices growing and also explained the key role of India. The account of Marco Polo fueled a desire by Europeans to establish direct trading links. At the same time great improvements were made in maps in the 14th century. Information provided by travelers was refined by explorers who began to sail south along the African coast. Europeans also made great strides in shipbuilding. Large capacity ships called galleons were adopted, which greatly reduce the cost of transporting goods over distances. Finally Portuguese sailors in the 15th century established direct contact with the source of spices.

【正确答案】 B

【正确答案】 C