横向
1
Second lightest element
3
Ball of burning gas in space
7
Gas form of a liquid
8
Basic unit of life
9
Substance with pH below 7
纵向
2
Group of similar cells
4
Our home planet
5
Measure of matter in an object
6
Naturally occurring inorganic solid
Second lightest element
Ball of burning gas in space
Gas form of a liquid
Basic unit of life
Substance with pH below 7
Group of similar cells
Our home planet
Measure of matter in an object
Naturally occurring inorganic solid