How do scientists measure the amount of dissolved substances in water?

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

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

Apuppy’s tendency to chew is inherited through which of the following? a. through learned behavior b.through genes c. through seasonal cycles d. through hibernation