请教for 的用法

余饭饭

之前看到CD上说for doing是指事物的具体用途，而to do 则有表目的意思for doing有持久性的趋势，而to do 则往往是一次性的行为

#OG 2018 SC267

Kudzu, an Asian vine that has grown rampantly in the southern United States since introducing it in the 1920s to thwart soil erosion, has overrun many houses and countless acres of roadside.

A  that has grown rampantly in the southern United States since introducing it in the 1920s to thwart

B  that has grown rampantly in the southern United States, since it was introduced in the 1920s for thwarting

C  that has grown rampant in the southern United States since it was introduced in the 1920s to thwart

D  growing rampant in the southern United States since introducing it in the 1920s for thwarting

E  growing rampantly in the southern United States, since it was introduced in the 1920s to thwar

有NN能解释一下这里的的for thwarting 为什么比to thwart 差么~是因为idoim 还是可以从语法上解释呢~

#OG

Long overshadowed by the Maya and Aztec civilizations, historians are now exploring the more ancient Olmec culture for the legacy it had for succeeding Mesoamerican societies..
      A  historians are now exploring the more ancient Olmec culture for the legacy it had for succeeding Mesoamerican societies

B  historian's exploration is now of the more ancient Olmec culture's legacy to the Mesoamerican societies succeeding them

C  the legacy of the more ancient Olmec culture to the Mesoamerian societies that succeeded them is what historians are now exploring

D  the more ancient Olmec culture is now being explored by historians for its legacy to succeeding Mesoamerican societies

E  the Olmec culture is more ancient and had a legacy to succeeding Mesoamerican societies that historians are now exploring

这道题的OA是D，有NN能帮忙解释一下for its legacy to succeeding ...为什么对么~

Thisis呱呱小

for 的用法，表“因为”，因为之后的Mosoamerican societies 的legacy

LucianLau

第一题，剩下 BC，可以不考虑 for 的问题，B 的 since 打了逗号，不知道是修饰主句还是从句，句意模糊。修饰主句就变成从一开始引入就已经超过其他植物了，这显然 absurb
另外，在 GMAT 中，表目的一般都用 to do 而不是 for doing。

第二题，剩下 DE，E 的 that 从句不知道是修饰 societies 还是 legacy，而这里 explore 的对象显然是 culture，所以 E 不好。