钢筋下料的基本原则是什么？
参考答案：先下长料后下短料，集中搭配下料。
播音员正常的语速讲话，每分钟约（）个字
A、100-120
B、120-130
C、130-150
D、180-200
I wonder why Jenny to us recently. We should have heard from her by now. [ ]
A. hasn't written
B. doesn't write
C. won't write
D. hadn't written
