The chemical that promotes phototropism is

Ausable water source is one that can be used by humans for drinking or agriculture. identify the water reservoirs as usable or unusable based on their current state. oceans rivers glaciers freshwater lakes groundwater

What is any method of measuring the age of an object or event in years, such as using atomic half-life?

Fossils of ancestors of the modern horses show a small 4-toed almost dog-like browsing animal named eohippus over time the horses got larger lost toes and changed to a grazing diet what is the best explanation of why this change occurred