焊接坡口的作用是什么?
参考答案:
坡口的作用是使电弧能深入到焊缝的根部,使根部能够焊透,钝边是为了防止烧穿,但是钝边的尺寸要保证第一层焊接能焊透,间隙也是为了保证能焊透。
The cartoon "Pleasant Goat and Big Big Wolf"appeals so much to children ________ it caters well to
their taste.[ ]
A. that
B. which
C. because
D. while
技术供水系统的水温、水压和水质不满足要求时,会有什么后果?