As the students only made a few mistakes,they __ (need not punish) so severely.我填了don't need to punish 錯了，正確答案為：need't have been punished請教一下，為什么要這么做，這兩者的區(qū)別，謝謝!

熱心網(wǎng)友

注意2點：1 students 是被punish, 所以要用被動語態(tài) be punished2 need't have done 是對過去的虛擬語氣，意思是“本不需要做某事”。因為學(xué)生犯的錯誤很少，他們本不需要被那么嚴(yán)厲地懲罰的。