your parents at home last week?[ ]
A. Is
B. Was
C. Are
D. Were
答案：D
下列（ ）是氧化还原反应
A． Zn+2HCL=ZnCL2
B． CaCO2 煅烧 CaO+CO2
C． BaCL2+H2SO4↓+2HCL↑
D． AgNO3+NaCL=AgCL+NaNO3
连续梁预应力管道应该符合设计要求，梁段预留管道位臵允许偏差应小于（）
A、4mm
B、5mm
C、10mm
