jovial <> lachrymose          快活的  <> 悲哀的                        

jovial <> mournful     快活的  <> 哀伤的                 

joyous <> grievous               高兴的  <> 令人忧伤的                    

judicious <> imprudent                          判断正确的  <> 轻率的               

   justify <> argue against                          证明  <> 反对                                  

kindle <> extinguish                               点燃  <> 熄灭                             

 kindle <> squelch                                  激发  <> 压制                                  

kindred <> dissimilar                             相似的  <> 不相似                          

 knack <> foolish                                   诀窍  <> 愚蠢                                  

knotty <> simple/easy                           棘手的  <> 简单的/容易的            

 kudos <> disparage                              荣誉  <> 失去荣誉                           

labile <> stable                                      不稳定的  <> 稳定的                    

  lacerate <> mitigate                               撕心裂肺  <> 减轻(痛苦等)              

lachrymose <> gladness                        悲伤  <> 快乐                                

 lackluster <> radiant                              无光的  <> 发光的                           

laconic <> loquacious                            简明的  <> 多嘴的