各位高手好
小弟有二个问题想请教
第一个:
32.
The Chicago and Calumet Rivers originally flowed into the St. Lawrence by way
of Lake Michigan, but having been redirected by constructing canals so that
the water now empties into the Mississippi by way of the Illinois River.
(A) Rivers originally flowed into the St. Lawrence by way of Lake Michigan,
but having been redirected by constructing
(B) Rivers had originally flowed into the St. Lawrence by way of Lake
Michigan, but they have been redirected by constructing
(C) Rivers, which originally flowed into the St. Lawrence by way of Lake
Michigan but have been redirected by the construction of
(D) Rivers, originally flowing into the St. Lawrence by way of Lake Michigan,
but having been redirected by the construction of
(E) Rivers, originally flowing into the St. Lawrence by way of Lake Michigan,
have been redirected through the construction of
删到剩BE挣扎
为何B的过去完成式不好??
答案是E
第二个问题:
43.
Although ice particles in the upper atmosphere benefit Earth in that they
reflect and absorb solar radiation, acting as a global thermostat and thus
keeping Earth from either burning up or freezing over, they also accelerate
the destruction of the ozone layer by reacting with chlorofluorocarbons
(CFC's).
(A) acting as a global thermostat and thus keeping Earth from either burning
up or freezing over, they also accelerate
(B) acting as a global thermostat and thus keeping Earth either from burning
up or freezing over, while also accelerating
(C) act as a global thermostat and thus keep Earth from either burning up or
freezing over, while also accelerating
(D) they act as a global thermostat that thus keeps Earth either from burning
up or freezing over, even though it also accelerates
(E) they act as a global thermostat to thus keep Earth from either burning up
or freezing over, but they also accelerate
答案是A
但为何A的acting不会错误修饰到solar radiation
这个问题困扰我很久了
因为像下面这题
42.
During the same period in which the Maya were developing a hieroglyphic
system of writing, the Aztec people also developed a written language, but it
was not as highly sophisticated as that of the Maya and was more pictographic
in nature.
(A) but it was not as highly sophisticated as that of the Maya and was
(B) but it was not as highly sophisticated as the Maya, being
(C) but, not as highly sophisticated as the Maya's, was
(D) not as highly sophisticated as that of the Maya, however, being
(E) not as highly sophisticated as the Maya's however, it was
D选项中的being修辞笔记说会错误修饰maya
所以不选
那42和43的分词究竟差在哪里
为何一个可以选一个不能选??
希望请各位大大赐教
谢谢~~

第一题应该是E, B的过去完成式没有接续点" target="_blank" rel="nofollow">
第三题应该也不是E..." target="_blank" rel="nofollow">

噢 不好意思 打错 答案是E没错!!感谢HI大指正 有些地方看错了

32.过去完成要搭配过去式 才有表达时间先后的意义42的being是没必要改成分词，因为不知道要修饰的逻辑主语是谁 ，A选项的用法比较好，就不要选改得比较不好的选项了43的这种用法是属于表因果关系的Ving句型，因为ice particle可以...对地球有益，所以act as ...and thus keep...不过其他选项有明显错误 就不要用较慢的方法了

感谢HI大和Q大的回答~~