Answer: A) At
Explanation for this question is being written.
Answer: C) At
Answer: A) Yes, you can use them to talk about the past.
Answer: B) Since 2015.
Answer: B) After
Answer: A) In
Answer: C) In
Answer: B) Before the ceremony.
Answer: B) On
Answer: A) FOR
Answer: A) For
Answer: A) On
Answer: C) For
Answer: A) ON
Answer: B) For
Answer: C) On
Answer: B) SINCE
Answer: B) In
Answer: A) Last
Answer: C) Since
Answer: A) By
Answer: B) Before
Answer: A) Ago
Answer: D) For
Answer: A) By Friday.
Answer: A) Before
Answer: B) The fourth of July.
Answer: B) In about five hours.
Answer: B) At
Answer: B) She has her math class before she goes to chemistry.
Answer: D) 20 minutes.
Answer: B) Preposition
Answer: C) The following afternoon.
Answer: A) During