關於試題:Eliza failed the math exam again. She ____________ much harder before taking it last week. (A)need to study (B)ought to study (C)should have studied (D)must have studied Eliza的數學考試又不及格了。她上星期應在考試前努力用功才對 (A) (現在)必須讀書 (B) (現在)應該讀書 (C) 過去應該(努力)讀書卻沒有 (D) 過去一定(很努力)讀書 should have+p.p. (表過去應做卻未做) must have+p.p (表對過去的推測)---過去一定如何....