更换风口时,高炉应()才能打开窥孔大盖。
A.减风低压
B.休风
C.增风低压
D.倒流休风
参考答案:D
----How beautiful the university is, Professor Wu.
----So it is. I ______ here for four years and my daughter is studying here too.
A. studied B. have studied C. was studied D. had studied
上述材料质量标准应达到( )。
A.国家标准
B.行业标准
C.总承包单位确定的标准
D.其他企业标准