天山新题20--15, 新问

15.   A substance from the licorice plant, 50 times sweeter than sucrose, was recently discovered, is not only a natural sweetener but also prevents tooth decay.

(A) A substance from the licorice plant, 50 times sweeter than sucrose, was recently discovered

(B) A substance, which was recently discovered, from the licorice plant, 50 times sweeter than sucrose,

(C) A substance from the licorice plant, which was recently discovered to be 50 times sweeter than sucrose,

(D) A substance from the licorice plant, 50 times sweeter than sucrose , which was recently discovered,（B）

(E) A recently discovered substance, 50 times sweeter than sucrose from the licorice plant,

看前人贴, 排除D时都说which修饰sucrose产生歧义, 一般情况下我也觉得如此, 可是碰巧有人拿出og114的例子, 反而让我疑惑

114. From the bark of the paper birch tree the Menomini crafted a canoe about twenty feet long and two feet wide, with small ribs and rails of cedar, which could carry four persons or eight hundred pounds of baggage so light that a person could easily portage it around impeding rapids.

这里也是并列修饰canoe, 难道which在后面不怕产生歧义修饰cedar吗?