[求助]GWD 12-32

Q32:

Prospecting for gold during the California gold rush was a relatively easy task, because of erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the surface by volcanic activity put gold literally within reach for anybody with a pan or shovel.

1. because of erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the surface by volcanic activity put gold literally within reach for
   
2. because of erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, gold-bearing riverbeds to the surface, and putting gold literally within reach of
   
3. owing to erosion, prehistoric glacier movement, and volcanic activity that had thrust ancient, gold-bearing riverbeds to the surface, and putting gold literally within reach of
   
4. since erosion, prehistoric glacier movement, and volcanic activity that thrust ancient, gold-bearing riverbeds to the surface, putting gold literally within reach for
   
5. since erosion, prehistoric glacier movement, and ancient, gold-bearing riverbeds thrust to the surface by volcanic activity put gold literally within reach of

答案E，

put gold literally 这儿为什么不是 putting???

是不是修饰activity ????

不明白

since erosion, movement, and riverbeds put gold within the reach of anybody

"thrust to the surface by volcanic activity" modifies "riverbeds"

这个题目很难啊，想了好久还是错了，顶一下，

不过还是觉得将 erosion, movement, and riverbeds 做并列不太通顺，他们都不是一个范畴的东西，怎么来平行？erosion, movement都是抽象名词，而riverbeds是具体的物体