Mining backfilling is restrained by relatively high filling cost.充填采矿由于充填成本较高而制约着其发展.High - water rapid - hardening backfilling with whole tailings is a new developed backfilling technology.全尾砂高水速凝充填技术是一项新近发展起来的充填技术.Its ...
针尖大的洞,也会刮进斗大的风.A tiny opening will let in a gust of wind.精确地说它不过象个针尖那么大.It was precisely like the point of a pin.针尖一般的阳光从窗帘的细孔里透进来.Pinpoint of sunlight came in throught minute holes in the curtains....