钢材的碳当量是指________的含量。
参考答案：将钢铁中各种合金元素折算成碳
None knows if _______ that boy, but if _______ him, her parents will be disappointed.
A．she will marry, she will marry
B．she marries, she marries
C．she will marry, she marries
D．she marries, she will marry
中小学德育的主要途径有哪些？
