The computers made by our company sell best, but several years ago no one could have imagined the role in the markets that they _________.

A．were playing

B．were to play

C．had played

D．played

国家标准规定，HRB400E钢筋是适用于有较高要求的抗震结构的钢筋牌号，该类钢筋应满足的要求中，钢筋( )之比不小于1.25。

A．实测冲击强度与实测拉伸强度

B．实测变形强度与实测冲击强度

C．实测抗拉强度与实测屈服强度

D．实测抗拉强度与伸长率