Using calcium chloridize and sodium phosphate dibasic, this paper synthesizes hydroxyapatite having hexagonal system at 40 ℃.本文以氯化钙和磷酸氢二钠为原料,在40℃温度下合成了具有六方晶系的羟基磷灰石....
这场战争必须速战速决，尽量兵不血刃。This war had to be fought fast and relatively bloodlessly.带锯齿刃的刀a knife with a serrated edge有四面刃头的箭是从石弓发出来的.An arrow with a four - edged head is shot from a crossbow....