The results of the first in the series. Which can not be aware of is that the water level dropped. Caused by dehydration of the plant or the evaporation of water.
From the experimental results in the problem set 1 Which cannot know whether the reduced water levels. Caused by dehydration of the plants, or due to evaporation of water.
The trial of the problem in the unit 1, which is not able to know that the water level is a decrease in the discharge of water from the plants or evaporation of water.