he ought to |hand in| his term paper yesterday that is what he could have done
热心网友
"hand in "应改为“have handed in"ought to/should 后面跟不定式的完成式（have done）表示过去本来应该做而实际却没有做的动作。例如；I should have come to attend your birthhday party last night, but I was too busy.ought to/should 后面跟不定式的完成式否定形式（not have done）表示过去本来不应该做而实际却做的动作。例如：You should not have told a lie to her just now.
热心网友
"hand in "应改为“have handed in"表示“本来应做，但未做”。