supposedly修饰Mediterranean，即之前已确定是祖先，但不确定祖先是不是地中海的石头（推测）；supposed修饰predecessors，即不确定是不是祖先。根据本句逻辑，大概表达的意思是，本来人们推测这些地中海的石头是megalithic monuments in Brittany的祖先，但是现在的碳14检测发现megalithic monuments in Brittany比地中海的石头还早两千年，因此原来推测出的“祖先”是错误的，因此选supposed更合适

https://www.manhattanprep.com/gmat/forums/confusion-regarding-placement-of-an-adverb-og-question-t1333.html

We can't say that something is nearly 2000 yrs as old as ; rather 2000 yrs older is more correct form.

这题和manhattan那个例句不一样，例句supposed修饰ancestor逻辑不符合，但这里就是要修饰ancestor，表示不确定是不是ancestor，而不是确定了ancestor不确定是不是地中海的

1.key takeaway
X is 200 times as old as Y -- CORRECT.
X is 200 years as old as Y -- WRONG.
X is 200 years older than Y--CORRECT
2.supposed修饰predecessors，表示推测可能是predecessors，
supposedly是副词不修饰predecessors，而是修饰Mediterranean，地中海地区的。

2000years more than 才对

地中海是确定的，那些石碑就在地中海边上，没法假想。只能假想前辈们。

A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

1.key takeaway
X is 200 times as old as Y -- CORRECT.
X is 200 years as old as Y -- WRONG.
X is 200 years older than Y--CORRECT
2.supposed修饰predecessors，表示推测可能是predecessors，
supposedly是副词不修饰predecessors，而是修饰Mediterranean，地中海地区的。

sc
A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

楼下key takeaway
A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

A: X is as old as B 是错的， x is 100 times as old as B 正确
B:
C: 同上
D:同下
E:supposedly 修饰错误

XXX

楼下小姐姐正解
key takeaway
A is 100 times as old as B. 正确
A is 100 years older than B. 正确
A is 100 years as old as B. 错误

X is 200 times as old as Y -- CORRECT. However, X is 200 years as old as Y -- WRONG.
it should be: X is 200 years older than Y