“主产品结构文件”的英文符号是()。
A.MRP
B.MPS
C.BOM
D.PIF
参考答案:C
Young as he is, he _______every minute to reading the English newspaper.
A.spends
B.takes
C.devotes
D.picks
干密度和压实系数可用来评定回填土的质量。