横向
1
Second lightest element
4
Group of similar cells
5
Compound containing oxygen
9
Tissue that contracts for movement
14
Naturally occurring inorganic solid
纵向
2
Measure of matter in an object
3
Preserved remains of ancient life
6
Force that attracts objects together
7
Icy body with a tail near the sun
8
Push or pull on an object
10
Unit of heredity
11
Glass that splits light into spectrum
12
Blocking of light by a celestial body
13
Our home planet