Sure! Here’s a rewritten version of the sentences:

Question 86: Who authored the report concerning air pollution?
→ By whom?

Question 87: My sister just finished sweeping the floor and doing the dishes.
→ The floor.

Question 88: I wasn’t aware that someone was recording our conversation.
→ I didn’t know that our...

Question 89: They are constructing a new highway around the city.
→ A new highway.

Question 90: The restaurant offers seafood every Monday.
→ Seafood.

Question 91: We need to inform Mary about our change of plans.
→ Mary.

Question 92: They didn’t provide any explanations regarding that.
→ Nothing.

Question 93: Individuals should direct their complaints to the head office.
→ Their complaints.

Question 94: The teacher assigned us two very challenging exercises.
→ Two very difficult exercises.

Question 95: His colleagues presented him with a gift upon his retirement.
→ He.

Question 96: We will deliver the results to you as soon as they are prepared.
→ You will.