定位焊缝如果有裂纹不必清除,可以被正式焊缝盖上。( )
参考答案:错
足月新生儿生理性黄疸的特点中除外()
A.生后2~3天出现黄染
B.10~14天黄疸消退
C.肝功能正常
D.食欲好
E.血清胆红素小于257μmol/L
Which of the following is true of world steel production
A.The steel industry still has a bright prospect on a global scene.
B.Steel consumption in the world registered a drastic cut.
C.Steel makers are drastically cutting down their production.
D.Better promotion is needed for improving sales of steel products.