单选题 Alice received an invitation from her boss, ______ came as a surprise.

【正确答案】 C
【答案解析】[分析]此题考查非限制性定语从句。在非限制性定语从句中,不能用that引导,要用 which;选项it和he都使后一句成为分句子,但两个分句不能单以逗号连接。