横向
1
Second lightest element
3
Solid with repeating atomic pattern
5
Absolute temperature scale unit
8
Blocking of light by a celestial body
11
Tissue that contracts for movement
13
Unit of heredity
纵向
2
Substance with pH below 7
4
Center of an atom or cell
6
Curved glass that refracts light
7
Our home planet
9
Natural satellite of Earth
10
Preserved remains of ancient life
12
Reddish electrical conductor