John opened the door. There _____ he had never seen before.[ ]

A. a girl did stand    

B. a girl stood      

C. did a girl stand    

D. stood a girl

焊缝中如果存在焊瘤则焊接金属的切线与基体金属之间的夹角（）

A、小于90度

B、等于90度

C、大于90度

D、与夹角无关