Answer :
It seems like you're asking about a laboratory experiment or simulation related to the effects of human activity on freshwater resources. Here are some possible answers to your questions based on typical scenarios:
1. **Where did the rainwater go?**
 - Rainwater typically follows the water cycle. Some of it may evaporate back into the atmosphere, some may infiltrate into the ground to recharge groundwater, and some may runoff into nearby bodies of water like lakes and rivers.
2. **What happened to the groundwater after a lake was added? What caused this change in the groundwater?**
 - Adding a lake may increase groundwater levels initially due to increased surface water infiltration. This change occurs because the lake provides a new source of water that can percolate into the ground, replenishing groundwater stores.
3. **What happened to the groundwater when pollutants were added to the lake?**
 - Introducing pollutants into the lake can contaminate the water, leading to the infiltration of polluted water into the groundwater. This contamination can degrade the quality of groundwater, making it unsuitable for consumption or other uses.
4. **What happened to the lake after it rained? Why do you think this happened?**
 - After rain, the lake level may rise due to direct precipitation falling into it and runoff from surrounding areas. This happens because rainwater accumulates in the lake, increasing its volume and water level.
5. **What happened to the groundwater after it rained? Why do you think this happened?**
 - After rain, groundwater levels may rise as a result of increased infiltration of rainwater into the ground. This happens because the soil becomes saturated with water, allowing excess water to percolate downwards and recharge groundwater.
These responses provide a general understanding of the potential outcomes in a lab experiment or simulation related to the effects of human activity on freshwater resources. Specific results may vary depending on the experimental setup and conditions.
