英语翻译It can be inferred from the passage that which of the fo

是这样：
the extent to which
the extent 为 介词to的宾语
which 指代 the extent.
the extent to which research on mycorrhizal fungi has progressed
整个意思是：关于 mycorrhizal fungi 研究的进度.
It can be inferred from the passage that which of the following has NOT been a factor influencing the extent to which research on mycorrhizal fungi has progressed?
“从这篇文章中可以推断出下面哪个（因素）不是影响菌根菌研究的（研究）进度的因素?”
注意时态：现在完成时,表示：在说上述这番话时“迄今为止”还在进行的…….
整句话完整的意思是：
从这篇文章中可以推断出：下面哪个（因素）不是影响（迄今为止仍在进行的）菌根菌研究的（研究）进度的因素?

意思就是：....的程度