15. Dialects in this country are mutually _____. People from two different speech communities communicate with each other without much difficulty. (A) intelligible (B) unique (C) vulnerable (D) offensive (E) hateful 二、英文字彙類比：每一題有兩組英文字，請依他們的相互關係找出答案。例如: doctor : symptom = detective : (A. story B. clue C. crime D. police E. mystery)。答案是 B，因為醫師依據症狀判斷病因，而偵探依據線索追尋犯罪證據。