横向
1
Tissue that contracts for movement
4
Nerve cell in the brain
5
Smallest unit of an element
10
Gas essential for breathing
11
Second lightest element
12
Center of an atom or cell
13
Curved glass that refracts light
纵向
1
The Red Planet
2
Element found in all living things
3
Amplified beam of light
6
Our home planet
7
Icy body with a tail near the sun
8
Unit of force
9
Hottest planet in solar system