What factor made evolution more very slowly for the first two billion years of life on earth?

Why does bubbling occur when vinegar mixed with baking soda

Several bodily responses are described below. for each response, determine what caused the change in homeostasis. body starts to sweat breathing rate increases amount of saliva produced changes body starts to shiver

Ruby is conducting an investigation. an advantage of her design is that she can use a large range of variables, with that she can not be sure that one variable is the cause of another. what kind of investigation is ruby most likely conducting?