The first step a biologist takes when deciding how to study life is to?
a- write a paper
b- make an observation
c- do an experiment
d- make a hypothesis

Which of the following is not a symptom of desertification? a) decrease in salt content of the soil b) lowering of the water table c) reduced surface water d) increased soil erosion e) loss of native vegetation

Any sound above what db can cause hearing loss in human beings

What environmental cues and landmarks do the geese use to determine the timing and direction of their migration over the mountains? how do they find their way?