GRE花粉文章中的一句话

cenpok

这是GRE经典的一篇文章中的一句话，我始终搞不清第一句分句的结构，are enormous是从何而来的呢？还请众位高人指点。
谢谢！


Because the potential hazards pollen grains are subject to as they are transported over long distances are enormous, windpollinated plans have, in the view above, compensated for the ensuing loss of pollen through happenstance by virtue of producing an ammount of pollen that is one to three orderds of magnitude greater than the amout produced by species pollinated by insects.

tongxun

Because the potential hazards are enormous

maryland

Because the potential hazards pollen grains are subject to as they are transported over long distances are enormous,

分析：
/pollen grains are subject to /as they are transported over long distances 在这里做定语从句修饰the potential hazards，省略引导词that,主干就是tongxun说的Because the potential hazards are enormous