Answer and Explanation:
1. A: Where is your sister's apartment? B: Her apartment is on Green Street.
Since "apartment" is a singular noun, we should use the third person singular of the verb be to refer to it - "is". The address is incomplete. When we only have the street name, we use the preposition"on".
2. A: Where do you study English? B: We study at the school around the corner.
We know we are supposed to use "study" because it is used in the answer. We need the auxiliary "do" for the question referring to the second person singular/plural. We use the preposition "at" to refer to a school when we perform the action of studying or attending classes.
3. A: Does your neighbor work at a bank? B: No. She works at a bookstore.
We know we are supposed to use "work" because it is used in the answer. We need the auxiliary "does" for the question referring to the third person singular. We use the preposition "at" to mention the place where someone works.
4. A: Where do your parents live ? B: They live at 58 Gray Street.
We know we are supposed to use "live" because it is used in the answer. We need the auxiliary "do" for the question referring to the second person singular/plural. We use the preposition "at" with complete addresses.
