甲、乙两物体的质量之比为3:4,则它们在同一地点物体所受重力之比为_________ 。若甲的质量为6kg,则乙的重力为_______ N(g=10N/kg)。
3:4;800
---Look, what have you done?
---Sorry. I think if I _____another chance, I’ll do it better.
A.give
B.will be given
C.am given
D.will give
从蛙的发育过程来看,它属于______发育.