Season 3——manhattan 54 （已点评）

sanlingjie

54. Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A   was an underground remnant of Earth's earliest days, sporadically erupting

B   had been an underground remnant of Earth's earliest days and sporadically erupted

C   was an underground remnant of Earth's earliest days, which sporadically erupted

D   would be an underground remnant of Earth's earliest days that sporadically erupted

E   was an underground remnant of Earth's earliest days, having sporadically erupted

The original sentence does not contain any errors. The verb clause "was an underground remnant of Earth's earliest days" is correct in tense (simple past "was") and number (singular "molten rock" paired with singular "was").  Moreover, the modifier "sporadically erupting through volcanoes" correctly modifies the preceding clause.

(A)CORRECT.  This choice is correct as it repeats the original sentence.

(B) This choice unnecessarily and incorrectly changes the simple past "was" to the past perfect "had been," which is used only when describing the earlier of two past actions. Moreover, the use of "and" here equates the geologists' false understanding of lava with the fact that it sometimes erupts through volcanoes.

(C) This choice improperly uses the relative pronoun "which" to modify "Earth's earliest days" instead of "molten rock known as lava."

(D) This choice incorrectly changes the simple past "was" to the conditional "would be." Moreover, the use of "that" implies that eruption through volcanoes was part of what the geologists erroneously believed about lava.

(E) In this choice, "having sporadically erupted" incorrectly places this modifier in the past tense, implying that lava no longer erupts through volcanoes.

注意：which一般是就近指代，还有就是注意情态动词的取舍，没有的不要随便加，有的不要随便去掉，总之不要改变句子的愿意，尽量。

vanchaser

我选C。
A选项的erupting分词修饰会有歧义，是修饰Geologists还是molten.
B选项的时态had been不对，因为molten一直都是remnant，不会是在地理学家认为之前是，而一直都是。
D选项的would 感觉有问题，不应该是将来时。后面的that不知道修饰是否会有歧义。
E选项的having erupted时态错误，不是一直在喷发。

CHRISTINE2010

A: erupting不正确，应该用被动，因为lava不会自己出来。（不确定）

B: 句子中后半句是一般现在时，而且没有过去的时间点，因此前半句用had been过去完成时不正确。

C: Correct（但是C中的which，虽然是唯一的指代，但是觉得有点累赘而且不太清楚。所以。。A和C还是不太清楚）

D: 这个句子讲的是科学事实，前半句讲的是过去认为的事实，因此前半句应该用一般过去时。would be不对。

E: 前半句正确。后半句have been表示从过去到现在，lava不可能从过去到现在一直喷，所以不对。
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看了答案，发现还是有基本的语法点不清楚。。。。继续学习~~

doudoulong1302

选A  
我感觉这道题和PREP08 188 OG 12 30非常像  都是主系表形式下的分词使用
B 的过去完成时态有问题 不存在过去的过去
C D都是以定语从句形式 定的是ROCK 定的跨度太大 甚至越过了谓语 不会对
E的完成时态有问题

南瓜0729

选C
A., erupting 修饰成分不对
E ,having erupted 修饰成分不对
B.D时态不对

zealdin

选A

sporadically erupting 起修饰作用。所以用ing形式

但是有点纠结于B的 ....and ... erupted.. 感觉该选项想表达一个parallel的意思，但是前面的had been时态又不正确

C。。which错，指代不明

D。。that 指代不明，且would时态错，这是一个虽然是推测的，但是已经存在的现象，而非即将发生的事

E。。having错

jofre

54. Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.
A   was an underground remnant of Earth's earliest days, sporadically erupting
B   had been an underground remnant of Earth's earliest days and sporadically erupted
C   was an underground remnant of Earth's earliest days, which sporadically erupted
D   would be an underground remnant of Earth's earliest days that sporadically erupted
E   was an underground remnant of Earth's earliest days, having sporadically erupted

选C
1. Geologists once thought使用一般过去式，that从句表示一种认知，应该跟随主句时态使用一般过去式，BD选项错；
2. 后半部分的短语erupt用分词形式的话，逻辑上看逻辑主语应该是underground remnan，但语法上逻辑主语是Geologists或the molten rock，AE选项错；
3. having sporadically erupted表示动作在the molten rock was an underground remnant之前发生，而实际上underground remnan不时（sporadically）会喷发出来，而非过去特定某时间发生，E选项错；
4. be动词一般不与动词形成并列结构，B选项错
5. that从句前不加逗号，表示限制性定语从句，但是从逻辑上看，这里应该是非限制性定语从句，选项D错

Jane412

选A
B：had been和erupted时态不对
C：which不是修饰紧邻的名词吗，那这里就不对了。。。
D：would时态不对
E：having erupted不对。好像prep里说，having done的这种形式要改掉

xeyyxzty

54. Geologists once thought that the molten rock known as lava was an underground remnant of Earth's earliest days, sporadically erupting through volcanoes, but they now know that it is continuously created by the heat of the radioactivity deep inside the planet.

A   was an underground remnant of Earth's earliest days, sporadically erupting
--right（排除法~~~）
B   had been an underground remnant of Earth's earliest days and sporadically erupted--erupted through volcanoes解释an underground remnant，并列后不对~~~还有had been 不知道对不对
C   was an underground remnant of Earth's earliest days, which sporadically erupted
--which指代days，错
D   would be an underground remnant of Earth's earliest days that sporadically erupted
--would be~X
E   was an underground remnant of Earth's earliest days, having sporadically erupted
--having done~不对吧

mahaofei001

纠结在AC中，就是因为没有搞懂什么样子的修饰在GMAT中是最好的问题。
A中逗号后的ing形式确实有对句子主语的修饰作用，然而此时它被置于一个that从句中了，所以它所修饰的主语应该还是the molten rock。
doudoulong1302说的那两个题，我也看了看，Neuroscientists, having amassed a wealth of knowledge over the past twenty years about the brain and its development from birth to adulthood, are now drawing solid conclusions about how the human brain grows and how babies acquire language.是说的这个吗？感觉这个和本题讲的还是有出入的，具体说不上来，等待讲解中。

C的话，which却是很歧义的指代days。两个相对比看，还是A的表述更好些。

最后要指出的是1#中指出的那种错误修饰确实存在，要小心啊！