Understanding Passage Completion: Fill in the Blanks

This question requires us to complete a passage by selecting the most appropriate words for the given blanks. We need to read the passage carefully and understand its context and flow to choose words that fit grammatically and contextually.

Let's look at the passage again:

Fundamentally, all human beings possess a combination of fixed inherited traits. All individuals possess the ________ (1) highly developed nervous system, backbones, erect posture, hair, etc. Therefore, ________ (2) among human beings arise only in _______ (3) changes of this basic pattern. Racial differences ______ (4) one of the finest distinctions and are based only on ______ (5) slight differences.

We are asked to fill in blank number 5.

Analyzing Blank 5

The sentence containing blank 5 is: "Racial differences ______ (4) one of the finest distinctions and are based only on ______ (5) slight differences."

The sentence states that racial differences are based *only* on "slight differences". We need to find a word that describes these slight differences in this context.

Let's examine the options for blank 5:

• hidden: If the differences were hidden, they wouldn't typically be the basis for visible distinctions like race.
• possible: Using "possible" suggests uncertainty about whether these slight differences exist or are relevant, which doesn't fit the statement that racial differences *are based only on* them.
• clear: While differences might be clear, using "clear" alongside "slight" can be slightly contradictory. "Slight" implies small or subtle.
• certain: "Certain" implies specific, definite, or particular. Racial distinctions are based on specific, identifiable slight differences in physical characteristics (like skin pigmentation, hair texture, facial features). Using "certain" here means these are particular, established slight differences that form the basis of racial classification.

Considering the context that racial differences are *defined* by these slight variations, "certain" is the most appropriate word. It indicates that these slight differences are specific and form the basis for the distinction.

Therefore, the word that best fills blank 5 is "certain".

Filling the Blanks (for context, focusing on Blank 5)

Let's consider possible words for other blanks to ensure overall flow, although we are primarily focused on blank 5.

• (1) common (All individuals possess the common highly developed nervous system...)
• (2) differences / variations (Therefore, differences among human beings arise...)
• (3) slight / minor (arise only in slight changes of this basic pattern.)
• (4) are (Racial differences are one of the finest distinctions...)
• (5) certain (based only on certain slight differences.)

The completed phrase relevant to our question is: "...based only on certain slight differences." This makes logical sense.

The final answer for blank 5 is "certain".

Revision Table: Key Concepts

Additional Information: Word Choice in English

Choosing the correct word is crucial for clear and effective communication. When filling blanks in a passage, consider the following:

• Meaning: Does the word convey the intended meaning in the sentence?
• Grammar: Does the word fit grammatically with the surrounding words (e.g., tense, number, part of speech)?
• Context: Does the word make sense in the overall topic and tone of the passage?
• Collocation: Do the words naturally go together (e.g., "make a decision" vs. "do a decision")?

In the case of blank 5, "certain slight differences" is a common and logical collocation describing specific, minor variations that serve as distinguishing features.