They became friends again that day. Until then, they _______ to each other for nearly two years.

A．didn't speak

B．hadn't spoken

C．haven' t spoken

D．haven' t been speaking

下列关于软件测试成本管理中资源估算的说法，错误的是______。

A) 估算主要通过分解技术、经验建模来实现
B) 软件测试成本很重要的是人力资源成本
C) 对人力资源来说，首先要进行工作量估算
D) 分解技术是指根据经验导出的公式来预测工作量和时间