The Trumpadministration’s proposal will give states wide latitude on how to regulate emissions from coal-fired power plants, even letting them opt out of the task altogether, which will enable some plants to carry on for longer than they would have otherwise.
第一个疑问：
请问老师，on how to regulate emissions...此结构能否视为：on the way in which states can regulate emissions...名词性关系从句的省略；继而产生的疑问是，是不是介词后的名词性从句肯定是名词性关系从句而不是名词性疑问从句？
第二个疑问：
句尾比较状从中的 would have 该如何理解呢？
第一个疑问：
请问老师，on how to regulate emissions...此结构能否视为：on the way in which states can regulate emissions...名词性关系从句的省略；继而产生的疑问是，是不是介词后的名词性从句肯定是名词性关系从句而不是名词性疑问从句？
答：名词性关系分句不允许省略成非限定形式。因此How to regulate只能是间接疑问句的省略式。你的疑问实质也就没有了。
第二个疑问：
比较分句使用缩减形式是常规而不是例外。than they would have为than they would have carried on的省略形式。
