Which of the following is NOT correctly matched with the organ system.
A. Anxiety- Nervous system
B. Nausea- Digestive system
C. Weight loss- digestive system
D. Joint pain-skeletal system

Which of the following statements best describes the relationship between the environment and human health? a. the environment is the only factor that affects human health. b. many aspects of the environment can have an impact on human health. c. human health is impacted by changes in climate. d. the environment has no impact on human health. select the best answer from the choices provided

On a recent expedition to a remote region of northern canada, scientists uncovered skeletal remains from about 100,000 years ago. surprisingly, all the skeletal remains, which included many species from differing biological families and spanned about two thousand years, showed evidence of experiencing temperatures in excess of 1000 degrees fahrenheit (or 538 degrees celsius). which of the following, if true, best explains the apparent paradox between the cold environment and the evidence of the bones experiencing hot temperatures? (a) chemical changes that naturally occur during the process of decay in only one north canadian species produce the same evidence of the species' skeletons being exposed to hot temperatures as the expedition scientists found. (b) a little over 103,000 years ago, a large fire is known to have occurred in northern canada. (c) strong evidence exists that as early as 70,000 years ago, homo sapiens around the world relied heavily on fire to cook animals. (d) in the same expedition and in roughly the same layer of excavation, scientists found rudimentary wood cutting and hunting tools used by early humans.

Ascientific idea becomes valid when it is what?