In winter, the diets of Japanese macaques, also known as snow monkeys, are influenced more by food availability than by...

Let's begin by understanding the meaning of this sentence. We'll use our understanding of pause points and segment the sentence as shown - understanding and assimilating the meaning of each segment bit by bit!

Sentence Structure

• In winter,
  • the diets of Japanese macaques,
    • also known as snow monkeys,
  • are influenced more by food availability than by food preference.

• Although the monkeys prefer to eat vegetation and land-dwelling invertebrates,
  • those food sources may become unavailable
    • because of extensive snow and ice cover,
  • (?) the monkeys to hunt for marine animals in any streams
    • that have not frozen over.

Understanding the Meaning

The first sentence sets up the context:

• In winter, snow monkey diets are influenced more by what food is available than by what they prefer to eat.

Now the second sentence gives us more detail:

• 'Although the monkeys prefer to eat vegetation and land-dwelling invertebrates'
  • This tells us what they WANT to eat - plants and insects/worms that live on land.

• 'those food sources may become unavailable because of extensive snow and ice cover'
  • Their preferred foods might not be accessible when there's lots of snow and ice.
  • "may become unavailable" is the main verb of this sentence.

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

• forces
• to force
• forcing
• forced

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

• '______ the monkeys to hunt for marine animals in any streams that have not frozen over'
  • So the monkeys end up hunting for water-dwelling animals in unfrozen streams.

The complete picture is:

• When snow and ice cover make the monkeys' preferred food unavailable, this situation causes/forces them to hunt for marine animals instead.

What do we notice about the structure here?

• We have a complete main clause:
  • "those food sources may become unavailable because of extensive snow and ice cover"
  • This has its main verb: "may become"

• After the comma, we need something that connects to this main clause and shows what happens as a result.

• "forcing the monkeys to hunt..." creates a descriptive phrase that shows the consequence of the food becoming unavailable.
  • This is using the -ing form (called a present participle) to create a modifying phrase.
  • The phrase describes the result of the main action.

So we need forcing - Choice C.

Grammar Concept Applied

Using -ing Verb Forms (Present Participles) to Show Consequence or Result

When you have a main clause and want to show what happens as a result or consequence, you can add a phrase beginning with a present participle (the -ing form of a verb, called a present participle in grammar terms):

Pattern: [Main clause], [present participle] + [rest of phrase]

Example 1:

• The storm knocked out power lines, forcing residents to use generators.
• Main clause: "The storm knocked out power lines"
• Result shown by participle: "forcing residents to use generators"

Example 2:

• The company closed three factories, eliminating hundreds of jobs.
• Main clause: "The company closed three factories"
• Result shown by participle: "eliminating hundreds of jobs"

In this question:

• Main clause: "those food sources may become unavailable because of extensive snow and ice cover"
• Result shown by participle: "forcing the monkeys to hunt for marine animals in any streams that have not frozen over"

The comma + present participle creates a modifying phrase that describes the consequence of the action in the main clause.