铝镁合金气焊用焊丝如何选择?为什么?
参考答案:
铝镁合金气焊时常选用比母材含镁量高的焊丝,因为镁与氧的新和力较大,气焊时,往往选用比母材含镁量高的焊丝,以补偿镁的烧损。
The policeman are looking for people________the accident which happened last night.[ ]
A.referred to
B.related to
C.linking to
D.connecting to
善治头项诸疾的腧穴首选()
A.合谷
B.列缺
C.委中
D.足三里
E.条口透承山