冷拉钢筋运行方向的端头应( ),防止在钢筋拉断或夹具失灵时钢筋弹出伤人。
A.固定
B.夹牢
C.设防护装置
D.远离作业人员
参考答案:C
I would have dropped in on him, but I ____ his address.
A.didn’t know
B.hadn’t know
C.don’t know
D.wouldn’t know
预防含钙结石复发()
A.氧化镁或维生素B6
B.氯化铵
C.碳酸氢钠和别嘌呤醇
D.卡托普利
E.碱性枸橼酸盐