试题题干
（）used to be said that Turkey was virtually the master of the Black Sea.
参考答案
正确答案：
试题解析
it 在句中做形式主语，真正的主语是that 引导的从句
（）used to be said that Turkey was virtually the master of the Black Sea.
it 在句中做形式主语，真正的主语是that 引导的从句