A non-restrictive modifier add information that does not restrict who the subject can refer to (compare to "The one Marlena that enjoys many subjects" -this one restricts the subject to a specific Marlena). Here it's "who enjoys many different subjects" - it adds additional information about her, but doesn't change the referent.
Answer:
If he studies he wont get paid anything but if he babysits he will earn 15 dollars so the opportunity to study will cost him $15
Explanation:
The rule is that when the conjunction and is used to connect two independent clauses to create one compound sentence, there should always be a comma before and. Having this in mind, the correct answer is the first choice - The library of congress houses over 147 million items, and it is the largest library in the world.
Answer:
the Correct answer is many strange things happened in Michigan in the 1960's
Explanation: