横向
1
Group of similar cells
5
Second lightest element
6
Chemical element in table salt
10
Substance with pH above 7
纵向
2
Amplified beam of light
3
Smallest unit of an element
4
Gas essential for breathing
7
Substance with pH below 7
8
Particle of light
9
Mass per unit volume
11
Icy body with a tail near the sun