<span>Trees grow below or above the timberline, or tree line, depending on the environmental conditions present. Alpine tree lines are common near or on mountains and mountain ranges. The weather above the timberline is too cold and possibly too dry for trees to grow and take root. Desert tree lines are common in and near deserts. The soil is too dry for the trees to take root and get the water and nutrients they require. Desert-Alpine tree lines are environments where the elevation is too high and the soil too dry to foster tree growth.</span>
His study was found to have a problem with <u>"validity".</u>
Conclusions drawn from analyzing study information are just satisfactory to how much they are resolved valid. validity is utilized to decide if look into measures what it planned to quantify and to surmised the honesty of the outcomes. Scientists regularly utilize their own definition with regards to what is viewed as substantial. In quantitative research testing for validity and reliability is guaranteed.
-inferior wepons
-disease
:)
those are the reasons...
Answer:
c. most people live in urban areas.