A research is madethe properties of compound cement consisting of Alite - sulphoaluminate cement and Portland cement. 研究了阿利特 - 硫铝酸盐水泥与硅酸盐水泥复合所制备的水泥的性能.
The three main expeditions were plowing through seas infested with U - boats.三个主要远征部队驶经充满潜艇的海岸.The war - chief could only give orders on military expeditions.酋帅仅仅在出征时才能发号施令.Some later expeditions fared better, though the...