已知空气的单位体积质量为0.00124g/cm3,将它用科学记数表示为______g/cm3.
0.00124=1.24×10-3.
故答案为:1.24×10-3.
角铁找正时,若不符合要求,除进行修刮之外,还可采用垫薄铜皮或薄纸片的方法使之达到要求。( )
— _____ do you go hiking?
— Once a week. [ ]
A. How much
B. How often
C. How long
D. How soon