中碳钢中铁素体和渗碳体比例适当，塑性、韧性适中切削性（）。
参考答案：好
Would you please keep silent? The weather report______and I want to listen.
A．is broadcast
B．is being broadcast
C．has been broadcast
D．had been broadcast
下列数据表明我国：
A、综合国力、人们生活水平上了一个大台阶
