主要成分：we need more actual facts
后置定語：on which to base our arguments
例句
we need to have it on which to base our policy?
一、句子分析：
主要成分：we need to have it
后置定語：on which to base our policy
二、該定語是個(gè)不定式短語,其中
1. which 指代上文的代詞 it,因此 on which to base our policy =to base our policy on it；
2. 由上可知 to 是動(dòng)詞不定式符號(hào)
3. base sth. on ... 意思是“把...建立在...的基礎(chǔ)上
三、可以把它改寫為從句：
We need to have it on which we can base our policy.
或者： We need to have it which we can base our policy on.
四、翻譯：我們需要擁有（或得到）把政策建立在它上面的這個(gè)東西(it 上文提到過,可以用上文提及的名詞取代本譯文中的“這個(gè)東西”).