单选题 In a way, Iˊm glad youˊve made the mistake, for it ______ as a warning to you. 的答案

成人教育远程网络教育函授网上考试【专科英语II】课程在线考试模拟试题正确答案解析，免费查看【专科英语II】作业答案。
题目内容：
In a way, Iˊm glad youˊve made the mistake, for it ______ as a warning to you.
题目选项

参考答案价值：100%