横向
1
Smallest unit of an element
3
Mass per unit volume
4
Compound containing oxygen
7
Solid with repeating atomic pattern
12
Nerve cell in the brain
纵向
2
Group of similar cells
5
Molten rock beneath Earth surface
6
Particle of light
8
Amplified beam of light
9
Chemical element in table salt
10
Infectious microscopic agent
11
Tissue that contracts for movement