预测为无突出危险工作面,每预测循环应留有不小于()m的预测超前距。A、2 B、3 C 发布时间:2019-07-21 18:44 │ 来源:www.tikuol.com 题型:单项选择题 问题: 预测为无突出危险工作面,每预测循环应留有不小于()m的预测超前距。A、2B、3C、4
题型:单项选择题 Last year it started to rain ________ we were watching the fireworks.[ ]A. asB. whileC. sinceD. as soon as 查看答案