求助！大NN帮帮我

ctjboy

碰到一道题
The yield of natural gas from Norway's Troll gas field is expected to increase annually until the year 2005 and then to stabilize at six billion cubic feet a day, which will allow such an extraction rate at least for 50 years' production.
A.2005 and then to stabilize at six billion cubic feet a day, which will allow such an extraction rate at least for
B.2005 and then to stabilize at six billion cubic feet a day, an extraction rate that will allow at least
C.2005 and then stabilizing at six billion cubic feet a day, with such an extraction rate at the least allowing
D.2005, then stabilizing at six billion cubic feet a day, allowing such an extraction rate for at least  
E.2005, then stabilizing at six billion cubic feet a day, which will allow such an extraction rate for at least
这道题通过判断平行结构，排除了除B外的所有选项，虽然是做对了，但是不太理解B选项的an extraction rate that will allow at least算是什么成分？应该不算独立主格作伴随修饰吧？？如果不是的话，除了语法笔记上写的独立主格，分词短语，形容词短语，单个形容词这些成分以外，还有哪些是能够做伴随状语的呢？？烦请NN能列举，帮助小弟总结，谢谢！

chillstone

这应该是个同位语结构an extraction rate指代six billion cubic feet a day.

小困蛇

句末同位语

mashengyi

你好 我想问一下问什么这个是同位语呢？ 同位语不是修饰的临近的一个名次么 求解

幸运四叶草