Choose the one that is a grammatically correct complete sentence. a. even though every river must sometime, somewhere, empty into the sea. b. i am very happy to hear of your success because no one deserves it more. c. no one attended classes on monday we were celebrating saturday’s football victory. d. what has happened to this economy, many americans want the answer to this question.

The correct answer would be option B, since it is the only one that makes complete sense.  Whereas the other options are missing puctuaction signs or some words to give order to the sentnces. For instance, in option A, it would be necessary to change some words or add some linkers to make the sentence correct. In option C, it would be necessary to have some commas to give better understanding to the reader of the phrase. Lastly, option D needs to have a question mark, since it is a question, and it is necessary to understand the sense of the sentence.  

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."

answer: this is easy, i found "it"

i will repeat the question again, "find it."

here, i located it.