A:a; the
B:a; a
C:the; a
D:the; the
He can do what he can the children in his neighborhood.
下表为某小组同学用大豆种子探究“种子萌发的环境条件”实验,他们探究的环境条件是
一座长方体花岗岩石碑,质量为4.2×103kg,底面积为0.5m2(g取10N/kg).求: