【正确答案】：
THE AMBIGUITY HERE IS CAUSED BY HOMONYMY.
(A) DUCK CAN BE UNDERSTOOD AS A NOUN MEANING A “KIND OF POULTRY” OR AS A VERB MEANING “LOWER ONE’S HEAD OR BODY QUICKLY, DODGE”, THIS AMBIGUITY CAN BE ELIMINATED BY ALTERING THE CONTEXT A LITTLE AS “THEY SAW HER DUCK SWIMMING IN THE RIVER.”
(B) BALL MAY MEAN A “ROUND OBJECT TO PLAY IN A GAME” AS WELL AS A “DANCING PARTY”. THIS AMBIGUITY CAN BE ELIMINATED BY ALTERING THE CONTEXT A LITTLE AS “THE BALL WAS ATTRACTIVE WITH NICE MUSIC AND A LOT OF PEOPLE”.
【题目解析】：这里的歧义是由同音异义词引起的。（a）"duck"可以被理解为意为“一种家禽”的名词或意为“迅速低下头或身体，躲避”的动词，这种歧义可以通过稍微改变上下文来消除，如“他们看见她的鸭子在河里游泳”。（b）"ball"可能意味着一个“游戏中的玩耍的圆形物体”以及一个“舞会”。这种歧义可以通过稍微改变一下上下文来消除，比如“舞会很吸引人，音乐很好，人很多”。