选B.首先,A和C都考察的是强调句,若去掉that,显然句意不通畅,而B项主要是:the person you want to meet hasn't arrived because he is ill ,表原因且去掉that句意通畅(不缺成分);
而A和C则不能表达出这层意思(B和C不缺成分,但不符合语境).
D项:It is that```because```无此形式,故可排除.
选B.首先,A和C都考察的是强调句,若去掉that,显然句意不通畅,而B项主要是:the person you want to meet hasn't arrived because he is ill ,表原因且去掉that句意通畅(不缺成分);
而A和C则不能表达出这层意思(B和C不缺成分,但不符合语境).
D项:It is that```because```无此形式,故可排除.