1.(25번문제) only whenthe man was coming down and had reached the height of the eaves did the expert call out,be careful! watch your step coming down!

여기서 왜 call이 오나요? 이미 동사 did가 있지 않나요?? to call이 와야 될것 같은데...

2. (26번문제) 86% of the buyers of new computers in 2004 ran the same programs they ran on their old computers.

여기서 old computer로 프로그램을 돌린게 new computer로 프로그램을 돌린 것 보다 분명 과거의 일이잖아요. 그러면 had run 등 시제를 구분해주어야 하지 않나요? 왜 같은 시제를 사용한거죠?3. (32번문제) their diet was more varied than previously thought.

여기서 왜 priviously가 되는지, 뭘수식하길래 부사가 쓰인건지 모르겠습니다..