I have seen in gmat questions that when one event takes place before another of the past, it is generally shown by "had" - past perfect is used.
There are plenty of questions in
OG 12. For instance,
Q19. The Iroquois were primarily planters, although they supplemented their cultivation of maize, squash, and beans with fishing and hunting --- because same time, same tense used. simple past and simple past
Q3. Although various 18th and 19th century American poets
had professed an interest in Native American poetry and had pretended to imitate Native American forms in their own works, it was not until almost 1900 that scholars and critics seriously
began studying traditional Native American poetry in native languages.
Here, the
OG states that past perfect had professed and had pretended designate a time (18th & 19th C) earlier than simple past tense so the second clause, explaining what happened around 1900, must use the past tense, and so it uses "began studying"
Q86. The results of the company's cost-cutting measures are evident in its profits,
which increased 5% during first 3 months of this year after they fell over the last 2 years...
(here i have changed it to they)The above underlined portion is incorrect because it fails to distinguish between the two sequentially ordered indicators, wherein the first indicator (increase of 5%) occurred after the indicator mentioned next (fell over the last 2 years)
Now, the correct option that clearly depicts the sequence of events is
which have increased 5% during the first 3 months of this year after falling over the last 2 years.
Okay , the sentence seems better to me, but then I could not grasp what was wrong in my modified version, the original option (
changed from it to they).
Now, coming to the present question, when soap operas
were first aired in 1920s, the event of moving to the daytime hours happens after that in the 1930s. This creates a divide in the two timeframes. Accordingly,
had been first aired in 1920s must be used...
Therefore, to me, the correct answer must be
Although early soap operas
had / had been first aired on evening radio in the 1920's, they were moved to the daytime hours
in the 1930's when the evening schedule became crowded with comedians and variety shows.
Even though this option doesnt exist, I do not understand why same tense can be used to modify two events taking place in different times with say approx 10 years between them.
Further, had / had been is what I could think.
Please clarify someone.