炼钢工艺对入炉铁水温度、磷、硫含量作了严格规定，对其它元素可不作要求。
参考答案：错
几个质数的连乘积一定是[ ]
A．合数
B．质数
C．质因数
D．偶数
As we know, paper is made wood, wood is made paper.[ ]
A. of; from
B. from; into
C.into; by
D. in; from
