The Dust Bowl was a period of severe drought that plagued the Great Plains of the US during the 1930s....

Sentence Structure

Sentence 1:

• The Dust Bowl
  • was a period
    • of severe drought
      • that plagued the Great Plains
        • of the US
          • during the 1930s.

Sentence 2:

• During this time,
• dust storms [?] over 100 million acres of land.

Sentence 3:

• They
  • even reached as far east as New York City.

Understanding the Meaning

Let's start by reading the first sentence:

"The Dust Bowl was a period of severe drought that plagued the Great Plains of the US during the 1930s."

This tells us:

• We're learning about a historical event called the Dust Bowl
• It was a time of severe drought (very little rain)
• It affected the Great Plains region
• It happened during the 1930s

Notice the time clues here:

• "was" tells us this is something in the past
• "plagued" is also past tense
• "during the 1930s" gives us a specific time in history

Now here's where we need to fill in the blank:

• "During this time, dust storms ______ over 100 million acres of land."

Let's look at our choices:

1. are affecting (present - happening now)
2. will have affected (future perfect - will be completed in the future)
3. will affect (future - will happen later)
4. affected (past - happened already)

What do we need?

• "During this time" refers back to the 1930s - that past time period
• We're describing what the dust storms did during that historical event
• The first sentence established we're talking about the past with "was" and "plagued"

So we need the past tense: affected

Now let's read the rest to see the complete picture:

• "They even reached as far east as New York City."
• "They" refers to the dust storms
• "reached" is also past tense - confirming we're describing past events
• This adds detail about how far these storms traveled

The complete picture:

• All three sentences describe what happened during the Dust Bowl in the 1930s
• All the verbs work together in past tense: was, plagued, affected, reached

What do we notice about the structure here?

• The passage establishes a clear time frame - the 1930s, a historical period
• When we describe events that happened during a specific time in the past, all the verbs describing those events need to be in past tense
• "During this time" is a key phrase linking the second sentence to the same time period as the first sentence

The correct answer is D. affected because it matches the established past time frame.

GRAMMAR CONCEPT APPLIED

Matching Verb Tense to the Established Time Frame

When a passage describes events that occurred during a specific time period in the past, all verbs describing actions during that period should be in past tense. This maintains consistency and makes the timeline clear.

How to identify the time frame:

• Look for time markers: "during the 1930s," "in 2005," "last year"
• Notice the tense of other verbs in the passage
• Pay attention to phrases like "during this time" or "at that moment" that refer back to an already-established time period

Pattern in this question:

Sentence 1 establishes the time frame:

• "The Dust Bowl was a period... that plagued the Great Plains... during the 1930s"
• Past tense verbs + specific past time = historical context established

Sentence 2 must match:

• "During this time" = during the 1930s (past)
• Therefore: dust storms affected (past tense matches the established time frame)

Sentence 3 confirms the pattern:

• "They reached as far east as New York City"
• Also past tense, maintaining consistency

Key principle: Once a passage establishes when events happened (past, present, or future), maintain that time frame consistently unless there's a clear signal that you're shifting to a different time period.