The roughly 20 million inhabitants of these nations looked hopefully to the future.
句中，roughly为副词，后边的成分是名词短语20 million inhabitants，副词修饰名词，这里怎么样理解？能否改为rough?
roughly 是修饰数词 20 million的，等于副词about，大约的意思。数词可以被副词修饰，表示数目的精准程度，比如exactly，nearly，almost，about等。
