The mass fraction of n - butene in mixed C 4 from catalytic cracking after etherized was approximately 40 %.醚化后的催化裂化混合C4中含有质量分数约为40%的正丁烯,是生产丙烯的优质原料....
He collapsed following a vigorous exercise session at his home.在家剧烈运动了一阵后他突然昏倒了。He plunged 300ft to the ground when his parachute collapsed.降落伞突然瘪了，他从300英尺的高空跌落到地面。The film company collapsed, leaving Chris jobless and mi...
It'd be fun, after the situation in Europe settles down, to take a trip over to France.等欧洲的局势平定下来后，去法国旅行一趟应该不错。Some movement in the building will occur as It'settles into the subsoil.楼房沉到下层土时,楼里就会有动静.While your...