钢管焊接时,有加固环的钢管,加固环的对焊焊缝应与管节纵向焊缝错开,其间距不应小于() 发布时间:2019-01-29 20:07 │ 来源:www.tikuol.com 题型:单项选择题 问题: 钢管焊接时,有加固环的钢管,加固环的对焊焊缝应与管节纵向焊缝错开,其间距不应小于()mm;加固环距管节的环向焊缝不应小于50mm。A.50B.100C.150D.200
题型:单项选择题 At the Olympic Games, only the athletes who have reached the agreed standard for their event will be______as competitors.A.desertedB.discussedC.admittedD.advertised 查看答案
题型:单项选择题 __________ Nancy at home last weekend? No, she __________. She was in the library with her friends.[ ]A. Is, isn'tB. Was, wasn'tC. Did, didn'tD. Was, isn't 查看答案
题型:单项选择题 二阶欠阻尼系统质量指标与系统参数间的关系是( )。A.开环增益K减小,衰减比减小,静差增大B.开环增益K减小,最大偏差增大、衰减比减小、调节时间增大、静差减小C.开环增益K增大,最大偏差增大、衰减比减小、调节时间增大、静差减小D.开环增益K减小,最大偏差增大、静差减小、调节时间增大 查看答案