用40Cr制造齿轮的典型热处理为()。A、正火 B、退火 C、调质 D、回火 发布时间:2019-07-30 11:16 │ 来源:www.tikuol.com 题型:单项选择题 问题: 用40Cr制造齿轮的典型热处理为()。A、正火B、退火C、调质D、回火
题型:单项选择题 There is no ________ in trying to talk George into joining us. He enjoys being alone.[ ]A. doubt B. wonderC. hope D. point 查看答案