横向
1
Mass per unit volume
4
Path of a planet around the sun
5
Nerve cell in the brain
7
Naturally occurring inorganic solid
9
Tectonic landmass section
12
Element found in all living things
13
Disturbance that transfers energy
纵向
2
Unit of force
3
Our home planet
6
Chemical element in table salt
8
Blocking of light by a celestial body
10
Push or pull on an object
11
Substance with pH above 7
14
Precious yellow metallic element
15
Natural satellite of Earth