充填时间
参考答案：
自液态金属开始进入型腔起到充满型腔止，所需的时间。
The sentence was so hard to understand that I had to have my teacher to explain it to me.
A B C D
土孔隙中水的类型有（）
A.2种
B.3种
C.4种
D.5种
