Commensalism is an interaction in which one individual benefits while the other is neither helped nor harmed. Example: Orchids (example of epiphytes)
The tree would contain carbon.
The hypothesis would be: Consumption of a single apple every day will reduce the number of visits to the doctor.
The hypothesis is a proposed explanation that is a starting point for further investigations. So, in this case, we assume that eating one apple a day will keep us healthy, without the need for the doctor.
Answer:
Diffusion rate is 1.96 × 
/s
Explanation:
Diffusion is the process in which the molecules of a substance propagates from a region of higher concentration to region of lower concentration through a semi-permeable membrane.
diffusion rate = 
Given that; diameter = 15 mm, time = 15 minutes.
The dye spread in a circular form, so that;
area = 
r = 
= 
= 7.5 mm = 0.75 cm
area = 
× 
= 1.7679
time = 15 minutes = 15 × 60 = 900 seconds
So that;
diffusion rate = 
= 0.0019643 /s
Diffusion rate is 1.96 × /s
Green roof do have several advantages over ordinary roofs as follows.
<h3><u>Explanation:</u></h3>
Green roof are defined as the roof over which a thin layer of soil is placed to grow a thin layer of grass or other plants. This have several advantages as follows:
A. Green roof help in reducing water logging in roofs, thereby reducing the dampening of the concrete, and increasing the longevity of the roof.
B. It is actually energy saving, by reducing the summer temperatures by evaporation and transpiration. It also maintains a warm room temperature in winter by reducing the heat loss.
C. It's also actually low in budget. Its initial cost is more than ordinary roof, but the maintenance cost is very low, if not nill.
D. Its a place for recreational activities. Greenery in urban areas are very rare sight, which can be met through this project.
E. Green roofs provide a chance for urban agriculture.
