塔式起重机的滑轮、起升卷筒等均应设有钢丝绳防脱装置,该装置与滑轮卷筒侧板最外缘的间隙 发布时间:2020-11-29 11:20 │ 来源:www.tikuol.com 题型:单项选择题 问题: 塔式起重机的滑轮、起升卷筒等均应设有钢丝绳防脱装置,该装置与滑轮卷筒侧板最外缘的间隙不应超过钢丝绳直径的()A.15%B.20%C.25%D.30%
题型:单项选择题 When _________ the match __________? A. is; taken place B. did; take placeC. was; happened D. was; happening 查看答案
题型:单项选择题 23. It's reported that at least one Chinese vessel________in the hands of attackers in Somalia so far.A.had beenB.has beenC.wasD.Is 查看答案
题型:单项选择题 复数α、β分别对应复平面内的点P、Q,O为坐标原点,若α2-2αβ+4β2=0,则△POQ是( ).A.等腰直角三角形B.等边三角形C.一锐角为60°的直角三角形D.顶角为30°的等腰三角形 查看答案