<u>Answer:</u>
<em>Several factors have to be considered while planting green roofs.
</em>
<u>Explanation:</u>
<em>Green roof is a roof with vegetation growing in it. The vegetation is usually grown above a waterproof cover.</em> Many factors have to be considered while installing a green roof.
First is <em>sunlight availability</em>. While installing green roofs it has to be ensured that its location has adequate sunlight availability. If not the plants that require less sunlight must be chosen. The roof should be <em>flat or have low inclination.</em> The maximum allowable inclination is 30 degree.
The choice of plants has to be made according to the climate of the region. <em>The dry or wet nature of the region’s weather decides the type of plants grown there. </em>
<span>D) An organism can “make a living” and survive in its niche.
Because niche refers to an organisms role in an ecological system; its position in the environment - how it survives and multiply.</span>
They all can be grouped together
This depends a lot on the area in which the vacant lot is located, but in general it can be assumed that many plans would come up through cracks in the concrete.