单选题 ______of the seven continents were placed in the Pacific Ocean, there would still be room left for another continent the size of Asia.
【正确答案】 B
【答案解析】解析：本题考查虚拟语气。空格所在句已有谓语动词，故首先排除[C]项。根据句中的were placed和would still be判断，句子为虚拟语气。选项中，只有if可以用于虚拟语气。