横向
1
Smallest unit of an element
3
Gas essential for breathing
7
Form of thermal energy
8
Our home planet
10
Naturally occurring inorganic solid
11
Magnetic metallic element
纵向
2
Nerve cell in the brain
4
Unit of force
5
Mass per unit volume
6
Molten rock beneath Earth surface
9
Unit of energy
12
Infectious microscopic agent