在溅渣护炉工艺中,为使溅渣层有足够的耐火度,主要措施是调整渣中的()含量。
参考答案:MgO
简述国际保理服务的作用。
The weather turned out to be very bad,()was more than we could expect.
A. what
B. which
C. that
D. it