In the following passage, a suitable word is needed to complete the blank: As long as we are unmindful of this _____, the quality of our educational curriculum as well as that of our teachers and students is likely to remain inadequate. Select the most appropriate word for the blank.

Introduction / Context:
This question is part of a cloze passage about the real purpose of education. The passage states that education is for life, not merely for a livelihood, and then remarks that as long as we are unmindful of this something, the quality of the curriculum, teachers and students will remain inadequate. The blank requires a noun that captures the central idea about education expressed in the opening sentence. Choosing the right word depends on understanding both the meaning of the passage and the collocation patterns of English.

Given Data / Assumptions:
- The passage begins with the statement: Education is for life, not merely for a livelihood. - The sentence containing the blank is: As long as we are unmindful of this _____, the quality of our educational curriculum as well as that of our teachers and students is likely to remain inadequate. - Options provided are: measure, resource, story and truth. - We assume the writer is making a serious philosophical point about the nature of education.

Concept / Approach:
To fill a blank in a comprehension passage, we rely on context, grammar and collocation. The word following this refers back to the key idea in the previous sentence. That idea, that education is for life and not just for earning, is a fundamental principle or reality. Among the options, the word that best captures a basic principle is truth. Measure, resource and story do not naturally refer to a deep guiding principle in this context. The chosen noun must also fit grammatically after this and collocate well with the phrase be unmindful of this.

Step-by-Step Solution:
Step 1: Identify what this refers to. It clearly points to the earlier statement about education being for life rather than just for livelihood. Step 2: Decide what type of word that earlier statement represents. It is a fundamental reality or principle that the author believes we should remember. Step 3: Evaluate each option. Measure means a unit of quantity or an action taken; resource refers to something used to meet needs; story refers to a narrative. None of these naturally describe a deep principle. Step 4: The word truth, however, is commonly used to refer to a basic principle or fact that people should recognise. The phrase unmindful of this truth is a natural and idiomatic expression. Step 5: Insert truth into the sentence: As long as we are unmindful of this truth, the quality of our educational curriculum as well as that of our teachers and students is likely to remain inadequate. The sentence now reads smoothly and conveys a clear meaning.

Verification / Alternative check:
We can verify by checking if the other options produce natural sentences. Unmindful of this measure sounds awkward because measure here would need a specific reference, such as a policy measure. Unmindful of this resource is also odd, since a resource is usually something we use, not a principle we keep in mind. Unmindful of this story would suggest a particular narrative, not a deep idea about education. Only unmindful of this truth fits both the serious tone of the passage and the idea that forgetting the real purpose of education harms the entire system. Thus truth is confirmed as the best answer.

Why Other Options Are Wrong:
Option A: Measure refers to a step or arrangement, but the passage is talking about a basic principle, not a specific policy step. Option B: Resource usually means a supply or asset, such as money or materials, and does not match the abstract idea described here. Option C: Story would make the opening philosophy about education sound like a mere tale, which conflicts with the serious tone of the passage.

Common Pitfalls:
A common mistake in cloze passages is to choose a word that fits grammatically but not conceptually. Candidates may focus only on the local sentence and ignore the key idea in the previous line. Another pitfall is to overthink and look for rare words, when the correct answer is often a common and simple term like truth. Always connect the blank to the central message of the passage and prefer words that preserve the tone and depth of that message.

Final Answer:
The suitable word to complete the blank is truth, so option D is correct.