Despite being cheap, versatile, and easy to produce, ________ they are made from nonrenewable petroleum, and most do not biodegrade...

Sentence Structure

• Despite being cheap, versatile, and easy to produce,
  • [?] they are made from nonrenewable petroleum,
    • and most do not biodegrade in landfills.

Understanding the Meaning

Let's start from the beginning:

"Despite being cheap, versatile, and easy to produce,"

• This opening phrase is describing something that has these three qualities:
  • cheap
  • versatile
  • easy to produce
• But what has these qualities? We need to keep reading.

This is where we have the blank. Let's look at the choices:

• A: there are two problems associated with commercial plastics:
• B: two problems are associated with commercial plastics:
• C: commercial plastics' two associated problems are that
• D: commercial plastics have two associated problems:

To see what works here, let's read the rest of the sentence and understand what it's saying!

After the colon: "they are made from nonrenewable petroleum, and most do not biodegrade in landfills."

Now let's understand what this complete sentence is telling us:

• The sentence is about commercial plastics
  • They have positive qualities (cheap, versatile, easy to produce)
  • BUT despite those good qualities, they have two problems

• The two problems are listed after the colon:
  • Problem 1: they are made from nonrenewable petroleum
  • Problem 2: most do not biodegrade in landfills

• Notice that "they" appears after the colon
  • "They" needs to refer to something
  • From context, "they" means commercial plastics

What do we notice about the structure here?

• The opening phrase "Despite being cheap, versatile, and easy to produce" is a describing phrase
  • It needs to describe whatever noun comes immediately after it
  • Whatever comes right after that comma should be what's "cheap, versatile, and easy to produce"

• What should be cheap, versatile, and easy to produce?
  • The commercial plastics themselves - not the problems!

• The word "they" after the colon needs to refer back to something
  • It should refer to "commercial plastics"
  • So "commercial plastics" needs to be the main subject

So we need Choice D: "commercial plastics have two associated problems:"

• This puts "commercial plastics" right after the opening phrase (correct)
  • So the plastics are what's cheap, versatile, and easy to produce
• This makes "commercial plastics" the subject (correct)
  • So "they" can clearly refer back to commercial plastics
• The colon introduces the list of the two problems (correct)

GRAMMAR CONCEPT APPLIED

Introductory Describing Phrases Must Describe What Comes Right After

When a sentence starts with a describing phrase (called a modifier in grammar terms) followed by a comma, that phrase must describe the noun that immediately follows the comma:

Pattern:

• Describing phrase, [NOUN BEING DESCRIBED] rest of sentence

Example 1:

• (correct) Correct: "Despite being expensive, the car sold quickly"
  • The car is what's expensive
• (incorrect) Incorrect: "Despite being expensive, the sale happened quickly"
  • Makes it sound like the sale is expensive (illogical)

Example 2:

• (correct) Correct: "After running for hours, the athlete collapsed"
  • The athlete is who ran
• (incorrect) Incorrect: "After running for hours, exhaustion overcame the athlete"
  • Makes it sound like exhaustion ran for hours (illogical)

In our question:

• The describing phrase is: "Despite being cheap, versatile, and easy to produce"
• What should this describe? Commercial plastics (not problems)
• So we need: "Despite being cheap, versatile, and easy to produce, commercial plastics have two associated problems"

Additional consideration: The pronoun "they" after the colon needs to refer to commercial plastics, which requires commercial plastics to be the main subject of the sentence, not just mentioned in passing or in a possessive form.