受精卵何时着床:
A.35cm,1000gB.45cm,2500gC.16cm,110gD.25cm,320gE.50cm,3400g胎儿身长,体重
参考答案:E
It's really a(an) ____ that Tony, a child of only two, can play the piano so well. [ ]
A. wonder
B. dream
C. preference
D. pleasure
在自由沉降条件下,二个等降颗粒()之比称为自由沉降等降比。
A、粒径
B、重量
C、体积
D、密度