湿视密度是指树脂在水中充分膨胀后的（）。
参考答案：堆积密度
The young woman has daughter.[ ]
A. a two-years-old
B. a two-year-old
C. two-year-old
D. two year's old
在□填上合适的数．□-42+36=56；□×（90-84）=48．
