Mary's sweater is the same colour ____________ Ann's.[ ]
A. and
B. as
C. or
答案:B
切除修复
管件安装前,要用干燥和洁净的压缩空气吹扫,一是为了清除管件内的灰尘和污物,而是为了检查管件上所焊的支管载入体和表座等零件有无漏钻,确保道路()