At the end of which period did nearly three quarters of all species of life on earth go extinct in a very short time interval cambrian jurassic triassic cretaceous

If you answer this i"ll give you brainiest and all these points me if you do i love you 7. a doctor is at work taking care of sick patients. she spends a few minutes trying to figure out why a particular patient is sick. she taps the patient's knee to test his reflexes. while she is examining him, the patient coughs on her. a) describe the function of the skeletomuscular system in this situation. (3 points) b) describe the function of the circulatory and respiratory systems in this situation. (3 points) c) describe the function of the immune system in this situation. (3 points) d) describe the function of the nervous system in this situation. (3 points) e) describe one way that any two of the doctor's body systems worked together in this situation. (3 points)

The table shows dates and appearance of index fossils. which rock layers can be dated most precisely? a) a layer containing both a fossil 4 and a fossil 3 b) a layer containing both a fossil 2 and a fossil 3 c) a layer containing both a fossil 1 and a fossil 4 d) a layer containing both a fossil 1 and a fossil 2

What is the most important inorganic material for livings things? ! due tomorrow!