《钢结构工程施工质量验收规范》规定,当钢材的表面有锈蚀、麻点或划痕等缺陷时,其深度不得大于该钢材厚度负允许偏差的( )。
A.1/2
B.1/3
C.1/4
D.1/5
参考答案:A
It took Li Ming an hour _____ his bike yesterday. [ ]
A. to repair
B. repairing
C. repaired
D. repair
下列物质加入稀盐酸中,溶液的pH不会明显改变的是( )
A.AgNO3
B.Fe
C.CuO
D.NaOH