待混凝土强度达到设计强度的( ),方可放松预应力筋。A.60% B.75% C.8 发布时间:2017-05-25 04:50 │ 来源:www.tikuol.com 题型:单项选择题 问题: 待混凝土强度达到设计强度的( ),方可放松预应力筋。A.60%B.75%C.80%D.90%
题型:单项选择题 The accuracy of scientific observation and calculations is always at the mercy of the scientist's timekeeping methods.A.under the control ofB.within the kindness ofC.beyond the reach ofD.out of the control of 查看答案