In experimenting we find out that sound travels with different velocities through different substances.在实验中,我们发现声音以不同的速度通过不同的物质而传播.I enjoyed experimenting with colours — it took me back to being five years old...我喜欢尝试各种颜...
1875年,来自东部的拓荒者在这个地区定居下来.Pioneers from the East settled in this region in 1875.1875年 —— G-F-斯威夫特设计的火车冷藏车厢开始使用.1875 -- G . F . Swift's refrigerated railway freight car is in use.1875年的宪法是各派对立力量的妥协产物.The Constitution o...
The commercial product however, containing silica and silicates, has a positive effect.然而含有硅石和硅酸盐的工业品都有肯定的效果.Frictional behavior is modified by colloidal silica or starch deposition.耐磨损性能可以通过在织物上沉淀胶状硅或淀粉一类物质而得到改善.Benefic...