横向
1
Force that attracts objects together
5
Path of a planet around the sun
6
Center of an atom or cell
10
Curved glass that refracts light
纵向
2
Substance with pH below 7
3
Tectonic landmass section
4
Reddish electrical conductor
7
Preserved remains of ancient life
8
Infectious microscopic agent
9
Gas essential for breathing