如果发50辆局车,每辆最大装60吨,如果要装7吨/卷,问最多能装多少个卷?
参考答案:
最大卷数=(60/7)×50≈8×50=400(卷)
— Does your Dad quit smoking, Jenny?
— Yes, but he ____ for almost ten years. [ ]
A. smoked
B. was smoking
C. has smoked
D. had smoked
下列关于石膏模型的说法,错误的是()
A.在15分钟内初凝
B.1小时基本凝固
C.24小时完全凝固
D.24小时其强度达到最高
E.初凝时不可修整,24小时时则容易修整