—Hey,thewashinguphasbeendone!—That

問題詳情：

— Hey, the washing up has been done!

— That ________ Cynthia. She's always helpful.

A. need have been  B. could have been  C. should have been  D. must have been

【回答】

D

知識點：虛擬語氣與情態動詞

題型：選擇題