横向
1
Second lightest element
3
Ball of burning gas in space
5
Unit of heredity
6
Positive particle in nucleus
9
Solid with repeating atomic pattern
10
Biological catalyst
11
Center of an atom or cell
12
Preserved remains of ancient life
13
Our home planet
纵向
2
Path of a planet around the sun
4
Curved glass that refracts light
6
Tectonic landmass section
7
Blocking of light by a celestial body
8
Molten rock beneath Earth surface