A:what to take place
B:what Tom has happened
C:what is happening
D:what the matter had bee
测量对象
质量m/kg
G/N
比值g/N•kg﹣1
物体1
0.1
0.98
9.8
物体2
0.2
1.96
物体3
0.3
2.94
世界上首先证明光合作用需要光的科学家( )