Casting DisplayObject.parent makes controlling parent movie clips hard.
向上溯型DisplayObject . parent使得父对象的clips很难控制。
2
Adopting the method of the solid-liquid composite casting, the new type anti-impact and anti-wear hammer head, in witch the soft material and hard material are alternately arranged, were made.
采用固-液复合铸造的方法，制造出一种软硬材料相间、抗冲击及耐磨性能高的复合锤头。
3
It is hard to build a precise math model for counter-gravity casting process for its time lag, uncertainty and complexity.