填空题 A r（） is often seen as part of a word， but it can never stand by itself although it bears clear， definite meaning.

填空题 Clear [1] and dark[]are allophones of the same one phoneme /1/.They never take the same position in sound combinations， thus they are said to be in c（） distribution.

填空题 In the course of time， the study of language has come to establish close links with other branches of s（） studies， such as sociology and psychology.