要将一个句子改写成名词，你可以采用以下几种方法：

将系动词和表语改成同位语

原句：Export Tax Rebate is an essential method for China's Macroeconomic control.

改写后：Export Tax Rebate, an essential method for China's Macroeconomic control.

将一般疑问句变成名词性从句

原句：Whether he will come has nothing to do with me.

改写后：Whether he will come is the sentence that has nothing to do with me. 或者简化为：Whether he will come is what has nothing to do with me.

将句子改为主语从句

原句：He will come tomorrow.

改写后：That he will come tomorrow is certain.

将句子改为宾语从句

原句：I know he is coming tomorrow.

改写后：I know that he is coming tomorrow.

将句子改成表语从句

原句：The problem came up at the meeting.

改写后：The problem that came up at the meeting is whether we had enough money to build the new gym.

通过这些方法，你可以将不同类型的句子改写成名词形式，从而使句子在语法和表达上更加丰富和准确。希望这些例子对你有所帮助!