Question

I got up early that morning, but I _____ so because I had no work to do. A．mustn’t have done.

I got up early that morning, but I _____ so because I had no work to do. A．mustn’t have done B．didn’t need to do C．needn’t have done D．can’t have done

Answer 1

C

needn’t have done表示“过去不必做而做了某事”，若表示“不必做某事（且实际上未做）”则用“didn’t / don’t / doesn’t need to.”