Tenses: past perfect MCQ - Practice Questions with Answers

The sentence refers to two past events: borrowing the books happened first, and the friend came later to collect them. The speaker's reading of only one book was completed before the later past moment of the friend's arrival, so the past perfect "had read" is required. "Read" alone is simple past and does not clearly mark the earlier past action. "Will have read" points to a future completion. "Have read" is present perfect, which does not fit with the past-time frame created by "came" and "was embarrassed".