Biomimicry is a design approach that applies solutions observed in natural systems to human engineering challenges. The Eastgate Centre in...

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

• Biomimicry is a design approach
• that applies solutions observed in natural systems
• to human engineering challenges.

• The Eastgate Centre in Zimbabwe,
• a building that maintains comfortable temperatures
• without conventional air conditioning
• by mimicking the complex ventilation systems
• found in termite mounds,
• [?] the effectiveness of passive cooling strategies.

Understanding the Meaning

The first sentence gives us context:

• Biomimicry is about taking solutions we see in nature and applying them to human engineering problems.

Now the second sentence gives us a specific example:

• 'The Eastgate Centre in Zimbabwe'
  • This is a particular building being introduced.

Then we get a lot of descriptive information about this building:

• 'a building that maintains comfortable temperatures without conventional air conditioning by mimicking the complex ventilation systems found in termite mounds'
  • So this building keeps a comfortable temperature
  • without using regular air conditioning
  • by copying the way termite mounds naturally ventilate themselves.

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

1. have demonstrated
2. demonstrates
3. demonstrate
4. are demonstrating

The choices are showing us different forms of the verb "demonstrate" - some singular, some plural. To see what works here, we need to identify what the subject of this verb is.

What do we notice about the structure here?

• The subject of this sentence is 'The Eastgate Centre in Zimbabwe'
  • This is a single building - it's singular.
  • Even though there's a long descriptive phrase between commas telling us more about the building, that phrase is just extra information.
  • The main subject is still 'The Eastgate Centre.'

• If we mentally remove the descriptive part, we get:
  • 'The Eastgate Centre in Zimbabwe _____ the effectiveness...'
  • Now it's easier to see: we need a singular verb to match 'The Eastgate Centre.'

• Looking at our choices:
  • 'have demonstrated' - plural (we say "they have")
  • 'demonstrates' - singular (we say "it demonstrates")
  • 'demonstrate' - plural (we say "they demonstrate")
  • 'are demonstrating' - plural (we say "they are")

So we need demonstrates - the singular form.

The complete sentence is saying:

• This building (the Eastgate Centre) demonstrates - or shows/proves - that passive cooling strategies (cooling without regular AC) can be effective.

GRAMMAR CONCEPT APPLIED

Matching Verbs to Their Subjects When Separated by Descriptive Information

A verb must match its subject in number - a singular subject takes a singular verb, and a plural subject takes a plural verb. This rule stays true even when the subject and verb are separated by commas and descriptive phrases.

The pattern:

• Subject + descriptive phrase set off by commas + verb
• The descriptive phrase (called an appositive or noun modifier in grammar terms) doesn't change what the subject is
• You need to identify the true subject and match the verb to it

Example 1:

• The scientist, along with her research assistants, presents the findings.
• Subject: "The scientist" (singular)
• Descriptive phrase: "along with her research assistants"
• Verb: "presents" (singular to match "scientist")

Example 2:

• The discovery, a finding that would overturn current theories, requires further verification.
• Subject: "The discovery" (singular)
• Descriptive phrase: "a finding that would overturn current theories"
• Verb: "requires" (singular to match "discovery")

In our question:

• Subject: "The Eastgate Centre in Zimbabwe" (singular)
• Descriptive phrase: "a building that maintains comfortable temperatures without conventional air conditioning by mimicking the complex ventilation systems found in termite mounds"
• Verb: "demonstrates" (singular to match "Centre")

The key strategy: When you have a long phrase between the subject and verb, mentally remove it temporarily to see the basic subject-verb relationship clearly: "The Eastgate Centre...demonstrates."