The indicator of presence or absence of a word in search is used in which mode?

Answer: Option B

This question is about how we search for things in a database using MySQL. Think of it like searching for a specific book in a library.

Imagine you want to find a book with the word "adventure" in its title. You might use different ways to search:

Option A: Natural Language - This is like asking a librarian, "Can you help me find a book about adventure?" It's more flexible, but might not be as precise.

Option B: Boolean mode - This is like using a very specific filter. You could say, "I want books with the word 'adventure' in the title, but NOT 'fantasy'." It's more precise, using keywords like "AND", "OR", and "NOT".

Option C: Query Expansion - This is like asking the librarian to suggest similar books based on your search. It's about broadening your search to find related results.

Option D: Cross mode - This isn't a common search mode in MySQL.

So, the answer is Option B: Boolean mode. This mode lets you directly specify if a word is present or absent in your search, using those keywords we mentioned.

Think of it like using a search engine where you can use "AND" and "NOT" to refine your search results!