容量350L自落式搅拌机,坍落度≤30mm时,每盘的最短搅拌时间为( )。
A.60s
B.90s
C.120s
D.150s
参考答案:C
If you take __________risk of not wearing a seat belt, you will be at __________risk.
A./; /
B./; the
C.the; /
D.the; the
薄板坯连铸可用于中、小型钢厂。