应该改为:Rock units are first emplaced either by deposition onto the surface or by intrusion into the overlying rock.
either ...or... 要使用parallel structure. 即使母语的人也会出现这种错误,这也是为什么国外写作教材一般都强调这一点。
Rock units are first emplaced either by deposition onto the surface or intrude into the overlying rock.
在这句话中either为什么在emplaced的后面,这给我了一种错觉就是并列成分会是by...,岩石块要么被什么什么存放,要么被什么什么存放。但是!or后面又重新跟了一个谓语,这让我觉得句子不对称。我觉得这个句子改为这样比较好:1.Rock units (either)are first emplaced by deposition onto the surface or intrude into the overlying rock.
请问老师我的理解哪里出现了问题?