横向
1
Precious yellow metallic element
3
Smallest unit of an element
6
Group of similar cells
7
The Red Planet
纵向
2
Chemical element in table salt
4
Our home planet
5
Substance with pH below 7
8
Fourth state of matter
Precious yellow metallic element
Smallest unit of an element
Group of similar cells
The Red Planet
Chemical element in table salt
Our home planet
Substance with pH below 7
Fourth state of matter