现场常用的防砂方法中,()对地层产能的影响最小。A、机械防砂 B、化学防砂 C、砂拱 发布时间:2017-07-14 18:58 │ 来源:www.tikuol.com 题型:单项选择题 问题: 现场常用的防砂方法中,()对地层产能的影响最小。A、机械防砂B、化学防砂C、砂拱防砂D、热力焦化防砂
题型:单项选择题 It is important for us to know how ______ requests politely. [ ]A. to make B. making C. make D. made 查看答案