— Why haven’t you asked her to come here?

— She _______ an important experiment when I found her and she _______ it.

A．had done; didn’t finish

B．was doing; hasn’t finished

C．did; wouldn’t finish

D．did; hadn’t finished

根据《建筑设计防火规范》，乙类火灾危险性的生产场所，厂房耐火等级应是（）.

A.一级

B.二级

C.三级

D.四级