- 搜標題
- 搜題干
- 搜選項
單項選擇題
普碳鋼要求[P]含量（）。
A.≥0.045%
B.≤0.045%
C.≥0.0045%
D.≤0.0045%
A.≥0.045%
B.≤0.045%
C.≥0.0045%
D.≤0.0045%
