题型:填空题 With so many Western companies, banks, and others setting up offices here, our telephone directory can not _____ and has to be updated every few days.A.keep backB.keep upC.take backD.take up 查看答案
题型:填空题 以下有关水泥抗压强度试验说法正确的是()A.抗压强度在试件的侧面进行B.半截棱柱体试件中心与压力板受压中心差应在±0.5mm内C.棱柱体露在压板外的部分约有15mmD.整个加荷速率为(2400±200)N/SE.整个加荷速率为(2200±100)N/S 查看答案