Answer: C) Had read.
Explanation for this question is being written.
Answer: B) Had met.
Answer: C) Eric had taken piano lessons as a little kid.
Answer: B) Had started.
Answer: C) Had studied.
Answer: B) Past perfect.
Answer: B) Hadn't noticed.
Answer: B) Had answered.
Answer: B) Had done.
Answer: B) Had left.
Answer: A) Had, completed.
Answer: A) Had gone out.
Answer: B) Had already left.
Answer: A) Had opened.
Answer: D) Had been cleaned.
Answer: B) Had
Answer: C) Found-had just left.
Answer: B) Had already appeared.
Answer: B) HAD EXPLAINED.
Answer: B) Had / rained.
Answer: C) Had sprayed-caught.
Answer: D) Had / already / eaten.
Answer: A) Couldn't drive / had lost.
Answer: B) Hadn't destroyed.
Answer: C) Had left.
Answer: A) Had
Answer: A) Past perfect.
Answer: C) Were
Answer: B) Had never visited.
Answer: C) Had let.
Answer: C) Had heard.
Answer: C) Had launched.
Answer: C) Had finished.
Answer: B) Had finished.
Answer: D) Had bought .
Answer: A) Past perfect tense.
Answer: C) Had repaired.
Answer: B) Hadn't he?
Answer: C) HAD
Answer: B) Had fallen.
Answer: A) But, I had exams at the university.
Answer: D) Had ended.
Answer: A) Had won.
Answer: B) Had eaten.
Answer: C) Had travelled.
Answer: C) Had never seen.
Answer: A) Had already been eaten.
Answer: B) Had passed.
Answer: B) Had just finished.
Answer: B) Had you read.
Answer: D) Had
Answer: B) Had invented.
Answer: A) Had met.