In the following passage about the value of books, choose the most appropriate word to complete the blank: The books contain all the great _____ of the leaders of the world.

Introduction / Context:
This question focuses on another blank in the passage that praises books as our friends and guides. It states that books contain all the great something of the leaders of the world. The missing noun must represent what books preserve from great leaders. In educational and motivational writing, authors usually say that books preserve the ideas or thoughts of great leaders. The correct answer should reflect this sense and fit grammatically with the structure great _____ of the leaders.

Given Data / Assumptions:
- The relevant portion is: The books contain all the great _____ of the leaders of the world. - Options are feel, thoughts, idle and money. - The passage is positive and respectful about books and leaders. - Books are known to preserve ideas, experiences and knowledge.

Concept / Approach:
We must choose a noun in plural form that can be described as great and that leaders are known for. Thoughts is an obvious candidate because leaders are remembered for their thoughts, ideas and philosophies. Feel in this form does not work as a noun in this position, idle is an adjective that does not match the structure, and money is not what the passage is likely to highlight about leaders in a moral context. The phrase great thoughts of the leaders of the world is a common expression in moral science and value education texts.

Step-by-Step Solution:
Step 1: Insert thoughts: The books contain all the great thoughts of the leaders of the world. This makes logical sense and reads smoothly. Step 2: Test feel. The books contain all the great feel of the leaders of the world is ungrammatical, because feel is not used as a countable noun here. Step 3: Test idle. The books contain all the great idle of the leaders of the world is incorrect because idle is an adjective, not a noun, and great idle does not express a clear idea. Step 4: Test money. The books contain all the great money of the leaders of the world sounds strange and contradicts the moral tone; books are valued for preserving wisdom, not wealth. Step 5: Conclude that thoughts is the only option that fits both meaning and grammar.

Verification / Alternative check:
We can verify by thinking about how school textbooks and moral lessons usually speak about leaders like Mahatma Gandhi, Nelson Mandela or Abraham Lincoln. They are praised for their great thoughts and ideals. Collections of quotations are often titled as great thoughts of world leaders. This reinforces that thoughts is the natural choice. No standard phrase talks about great money of leaders in the context of reading books for moral growth.

Why Other Options Are Wrong:
Option A: Feel is primarily a verb. As a noun, feeling is used instead, and it would still not be ideal in this context. Option C: Idle is an adjective meaning lazy or inactive and cannot fill the blank in this structure. Option D: Money shifts the focus from wisdom to wealth, which does not match the passage's emphasis on books as guides and friends.

Common Pitfalls:
A few learners might be tempted to think of feeling or ideals, but those words are not offered in the options. It is important not to invent new words, but to work only with the list given and choose the best match from it. Paying attention to part of speech and common collocations will quickly point you to thoughts as the correct answer.

Final Answer:
The missing noun is thoughts, so option B is correct.