● 题目：

　　In developing countries, where at least 16 cities are expected to have more than 12 million people each by the end of this decade, failing to give priority to public transport would be disastrous.

　　● 分析：

　　where at least 16 cities are expected to have more than 12 million people each by the end of this decade是插人语，是一个定语从句，修饰developing countries。全句主语是动名词短语failing to give priority to public transport.