Which text feature can help a reader determine the meaning of an unfamiliar word? A)thesaurus
B)index
C)glossary
D)dictionary

I belive it's glossary.

Explanation:

I think that because it's sorta like a mini-dictionary at the back of the book, but if the word is not a keyword you have to use a dictionary or modern-day cell phone to look it up on an online dictionary.  

this question is grammatically incorrect and is illegible to me so i can not answer.

the answer is:

when will (v) the books (n) be (v) due?

nouns refer to people (other than pronouns), places and things, whereas verbs describe actions and are usually part of the predicate of a sentence. finally, pronouns can work as nouns and identify the participants in speech.

in the example sentence, "will" is a verb part or auxiliary verb, "be" is an infinitive verb and "books" is a plural noun.