| 1. Plants give out faint ______ when they are thirsty. | 11 |
| 2. Many insects like to attack ______ plants. | 12 |
| 3. To test his theory, Robert is using a device that can ______ plant cries. | 13 |
| 4. A Healthy plant sounds ______ in Robert's test. | 14 |
| 5. The snapping pipes in plants make noises ten thousand times more quiet than a ______. | 15 |