• 2021-04-14
    【单选题】砂按细度模数分为粗、中、细三个规格,其细度模数分别为()。
    A. Mx =3.7~3.0为粗砂,Mx =2.9~2.3为中砂,Mx =2.2~1.6为细砂
    B. Mx =3.7~3.0为粗砂,Mx =2.9~2.2为中砂,Mx =2.1~1.6为细砂
    C. Mx =3.7~3.1为粗砂,Mx =3.0~2.3为中砂,Mx =2.2~1.6为细砂
    D. Mx =3.7~3.1为粗砂,Mx =3.0~2.2为中砂,Mx =2.1~1.6为细砂