Answer: C) Had explained.
Explanation for this question is being written.
Answer: C) Hadn't tried.
Answer: C) Had tossed.
Answer: B) PAST PERFECT.
Answer: D) Had been.
Answer: D) Unstated time before a past point.
Answer: A) Had ever done.
Answer: B) Had finished.
Answer: A) Had taken.
Answer: D) Had left/would have arrived.
Answer: A) Had finished.
Answer: C) Had recently bought.
Answer: B) Had met.
Answer: C) Had begun.
Answer: B) Hadn't seen.
Answer: A) Had sold.
Answer: B) Had had.
Answer: D) Had enjoyed/wanted.
Answer: B) Past perfect.
Answer: A) Had been.
Answer: C) Had taken.
Answer: D) I had not heard it before.
Answer: B) Had claimed.
Answer: B) Past Perfect.
Answer: B) Hadn't watched.
Answer: D) Had finished.
Answer: A) Before another past action.
Answer: B) Had, driven.
Answer: A) Had been / had.
Answer: B) Had written.
Answer: C) Had broken.
Answer: D) Past Perfect.
Answer: B) Had stopped.
Answer: A) Had
Answer: C) Had finished.
Answer: B) Hadn't eaten.
Answer: C) Had started.
Answer: B) Had studied.
Answer: A) Past Perfect Simple.
Answer: B) Had gone.
Answer: C) Had known.
Answer: B) Had slept.
Answer: A) Had been killed.
Answer: C) Had been.
Answer: C) Had submitted.
Answer: B) Had been.
Answer: C) Had gone.
Answer: B) Had left.
Answer: D) Kept / had seen.
Answer: B) Hadn't arrived.
Answer: A) Past perfect tense.
Answer: A) Pluperfect tense.
Answer: D) Had/ stolen.
Answer: D) Had visited.
Answer: B) Had told.
Answer: D) Had gone.
Answer: C) Had / finished.