In the sentence "the new bakery opens <u>in</u> a week" you only have the preposition IN. A prepositional phrase consists of preposition plus a noun, pronoun or gerund working as the object.
So, the prepositional phrase is "in a week", the object of the preposition is "week" (a noun) which is pre-modified by the indefinite article "a".
The dependent variable is that she bites her nails. Being nervous is an independent variable due to that it doesn't depend on anything said. However, in order for her to bite her nails, she has to be nervous as stated.
humans do not want their animals rebelling on their farms. Orwell writes, "Nevertheless, they were both thoroughly frightened by the rebellion on Animal Farm, and very anxious to prevent their own animals from learning too much about it"
