用较低的线能量进行单层焊接时,焊缝金属的强度和()均升高。
A.硬度
B.刚度
C.塑性
D.韧性
参考答案:A
I often read China Daily, ____of great help to my English study.
A.which I think is
B.which I think it is
C.that I think is
D.I think is
在感染中,临近恢复期出现的抗体是()
A.IgG
B.IgM
C.IgD
D.IgA
E.IgE