<u>Answer</u>: c. a and b
Trees play vital roles in the production of oxygen as well as the fixation of carbon from 
. As trees use nitrogen, phosphorus and water as nutrients for growth, their diminishing numbers would change the balance between these three elements significantly.
Thus, during rains, the water level will rise much faster and higher in the absence of trees. These could possibly lead to increasing cases of devastating landslides.
That would be called a source or head water
Answer:
Doppler effect is a change in frequency and wavelength of a wave. It is caused by the change in distance between the thing creating the wave (causer) and whatever is measuring seeing or hearing the wave (watcher or observer). Another word for "causer" is "sender".
HOPE THIS HELPED!!!!!!!!!!!!!! XDDDD
Actively transport molecules across the cell membrane
The answer to this would be d. :)
