阅读理解。 The total area of land on earth is about 149 million square kilometers, or about 39 percent of the total area of the earth. The average height of the land is about 750 metres above the sea level .The Eurasian (欧亚的) land mass is the largest with an area of 54,527,600 square kilometers .The smallest continent is the Australian mainland, with an area of about 7,614,600 square kilometers, which together with Tasmania, New Zealand, New Guinea and the Pacific Islands, is described as Oceania .The total area of Oceania is about 8,935,500 square kilometres, including West Iran which is political in Asia . The world's largest  peninsula (半岛) is Arabia ,with an area of about 3,327,500 square kilometres . The largest island in the world is Greenland, with an area of about 2,175,600 square kilometres. The largest island surrounded by fresh water is the Ilha de Marajo (4,022 square kilometres) in the mouth of the Amazon River, Brazil .The largest island in a lake is Manitoulin Island (2,766 square kilometres) in the Canadian section of Lake Huron . This island itself has on it a lake of 106 square kilometres called Manitou lake, in which there are several islands. 1. The area of Tasmania, of New Zealand, of New Guinea and of the Pacific Islands add up to about square kilometres . A.8,935,500 B.1,320,900 C.7,614,600 D.16,550,100 2. Oceania is made up of . (Suppose  I: Australia ;  II: Tasmania and New Zealand ; III: New Guinea and the Pacific Islands ) A. I and II B. II and III C. I and III D. I,II and III 3. Which of the following diagrams shows the correct relationship between Manitoulin Island(MI), Lake Huron (LH), Manitou Lake (ML) and the 'several islands' (SI) mentioned at the end of the passage ? 4. The largest island surrounded by fresh water is in . A. a river B. a  lake C. a sea D. an ocean