横向
1
Second lightest element
4
Magnetic metallic element
5
Biological catalyst
6
Blocking of light by a celestial body
10
Unit of electric potential
11
The Red Planet
12
Substance with pH below 7
纵向
2
Center of an atom or cell
3
Nerve cell in the brain
7
Infectious microscopic agent
8
Reddish electrical conductor
9
Naturally occurring inorganic solid