7.Magnesium Hydroxide flame retardment has some characteristics of retarding fire,reducing smoke,cheap priceand safe stuff etc,therefore,it is applied widely.
9.Synthetic method of phosphoretted fire retarding agent - YHD was researched.The property and application technique together with its application result of flame retardant YHD were mentioned here.
19.But we already saw in Chapter 10that the north–south axes and ecological barriers within Africa and the Americas retarded the diffusion of crops and domestic animals.
20.But though the profusion of government must undoubtedly have retarded the natural progress of England towards wealth and improvement, it has not been able to stop it.