The search engine's business model _____ around the fulcrum of trust.

“From where are they bringing their books? ________ bringing _______ books from _____.”

The words that best fill the blanks in the above sentence are

“A _________ investigation can sometimes yield new facts, but typically organized ones are more successful.”

The word that best fills the blank in the above sentence is

Out of the following four sentences, select the most suitable sentence with respect to grammar and usage.