对脱氧元素的要求,下列()说法不对。
A.脱氧产物要容易排除
B.脱氧元素的比重要小于钢液比重
C.脱氧元素对氧的亲合力必须大于铁,且要尽可能大
参考答案:B
When asked whether he could come over and have dinner with us, .
A.she said nothing
B.nothing was said by him
C.Tom nodded his head
D.they shook their heads
氢气为什么容易着火?