Select | | View | Download | | 16.1 Irritability | | |
| 16.2 Human eyes as the sense organs for detecting light | | |
| 16.3 Human ears as the sense organs for detecting sound | | |
| 16.4 Phototropic responses in plants | | |
| 16.1 Irritability (Bilingual) | | |
| 16.2 Human eyes as the sense organs for detecting light (Bilingual) | | |
| 16.3 Human ears as the sense organs for detecting sound (Bilingual) | | |
| 16.4 Phototropic responses in plants (Bilingual) | | |