SC's Question number - 761 , 762

761). The growing demand for housing, traffic congestion, and longer commuting trips has all but eliminated the cost advantage of owning a house in many rural communities.

(A) The growing demand for housing, traffic congestion, and longer commuting trips has

(B) Traffic congestion, the growing demand for housing, and longer commuting trips has

(C) Longer commuting trips, traffic congestion, and the growing demand for housing has

(D) Traffic congestion, longer commuting trips, and the growing demand for housing have

(E) The growing demand for housing, as well as traffic congestion and longer commuting trips, have

762). The growth of the railroads led to the abolition of local times, which was determined by when the sun reached the observer’s meridian and differing from city to city, and to the establishment of regional times.

(A) which was determined by when the sun reached the observer’s meridian and differing

(B) which was determined by when the sun reached the observer’s meridian and which differed

(C) which were determined by when the sun reached the observer’s meridian and differing

(D) determined by when the sun reached the observer’s meridian and differed

(E) determined by when the sun reached the observer's meridian and differing


Answers:

761). OA - D

A, B, C - incorrect - subject verb agreement - ..growing demand for housing, traffic congestion, and longer commuting trips has

E - incorrect - illogically suggests that there is growing demand for congestion and commuting trips

762). OA - E - .... local times are determined by X (past participle:times were determined in the past).....local times are differing from place to place till today (present participle:times are still differing)
Read about participles here

A, B ,C - incorrect - use of which is wrong. Relative pronoun which is used to refer to things and not time. Further in A and B use of was is wrong. We need were here to correctly modify times

D - incorrect - violating participle parallelism - use of differed is wrong: local times are differing from place to place not only in the past but also today. Present participle(differing) to logically illustrate the same.

GMAT Sentence Correction 113, 114

113). Scientists have recently discovered what could be the largest and oldest living organism on Earth, a giant fungus that is an interwoven filigree of mushrooms and rootlike tentacles spawned by a single fertilized spore some 10,000 years ago and extending for more than 30 acres in the soil of a Michigan forest.

(A) extending

(B) extends

(C) extended

(D) it extended

(E) is extending

114). Astronomers have theorized that the Big Bang governs the behavior of interstellar dust, particles that comprise the atoms and molecules created in the progenitive explosion and persisting in even the emptiest regions of space.

A. persisting

B. persists

C. persisted

D. they persist

E. are persisting

Answers:

113). A is the correct answer. This question tests the use of present vs past participle.

Subject in the given sentence is filigree

The filigree spawned by X not mentioned in the sentence some 10,000 years ago. Thus the use of past participle. Further, spawned by denotes passive voice which justifies the use of past participle.
As for the extending, it is still prevailing today in the Michigan forest so you cannot use past participle extended.

The present and past participles are used to describe the filigree, they act as adjectives

114). OA - A - This question again tests the use of present vs past participle
In the given sentence, we can clearly see that for the 1st participial phrase, the action of created happened in the past and is passive. The second participial phrase starting with persisting implies that the atoms and molecules are still persisting in the present, they are performing the action of "persisting" hence the use of present participle.

B - incorrect - violates parallelism (2nd participial phrase becomes a clause)

C - incorrect - use of persisted is wrong - illogically suggests that atoms no longer persisted

D - incorrect - violating parallelism

E - incorrect - violating parallelism (2nd participial phrase becomes a clause)