横向
1
Substance with pH above 7
3
Unit of energy
6
Basic unit of life
7
Ball of burning gas in space
11
Particle of light
12
Force that attracts objects together
纵向
2
Curved glass that refracts light
4
Unit of heredity
5
Positive particle in nucleus
8
Our home planet
9
Path of a planet around the sun
10
Preserved remains of ancient life