13-7=6;14+6=20;13-5=8
It was in the small house ___ was built with stones by his father ___he spent his childhood .
A.which , that
B.that , where
C.which , which
D.that , which
圬工梁、拱及墩台应具有要求的强度、刚度、抗渗、耐久性和整体稳定性,并经常保持状态良好。混凝土保护层中性化大于(),应及时处理。
A.10mm
B.15mm
C.20mm
D.25mm