落压成型原理。
参考答案：
利用质量很大的锤头或上模从高处落下时所产生的巨大的冲击力是，使毛料沿着成型模成形。
With Father's Day around the corner, I have taken some money out of the bank ________ presents
for my dad. [ ]
A. buy
B. to buy
C. buying
D. to have bought
矿井维修电工应携带两支与工作电压等级相符的验电笔并检查其（）状态。
