who is the girl （that）is crying.为什么不能用which?

who is the girl? Who is the beautiful girl who is the girl ( ) the hat?紧急! Who is the girl ( )blue.填空 who is the girl in red who is the girl （ ） red who is the girl a red hat? who is the girl?hui jia fen who is the girl () long hair? Who is the girl who is making a telephone call? Who is the boy and the girl 还是Who are the boy and the girl 请问Who is the girl?和Who is this girl?意思有什么不同? 填冠词 Who is the ( ) girl she is ( ) my sister Who is your cousin?The girl in( ) is Who is the girl that is making a telephone call? the girl who is talking with me is my heart! who is your cousin?The girl in y____ is she is not the girl who she is