Weathering is wearing down objects by elements in an environment
The answer is letter A. evolution always improves organisms. Darwin did not state this idea because he observed that even if evolution happened to species, there were some species that failed to adopt on the new environment. The other choices are his ideas of natural selection which states that an organism can survive if it has heritable traits that can adopt with the environment.
Answer: C
Explanation: Earth's atmosphere isn't very dense because it is made of air, which floats. Human beings are denser then air since they are solid, but not as dense as Earth's crust, which is rocky and the densest out of the three.
The correct answer is organ system level of organization.
A negative feedback example is Human body temperature - The hypothalamus of a human responds to temperature fluctuations and responds accordingly. If the temperature drops, the body shivers to bring up the temperature and if it is too warm, the body will sweat to cool down due to evaporation.
