People tend not to believe/accept things they can't see proof of with their own eyes or things that lack scientific evidence.
Continental drift is something that spans hundreds of thousands of years. People don't live that long to be able to see the position of the continents and land changing over time. Also when Wegener proposed this theory, he couldn't explain how continental drift occurred, so lacking scientific evidence, many people did not believe him.<span />
A molecule is a group of bonded atoms. Answer a, b, and c all have molecules. For example H2O has the molecule H2 in it. The only compound that doesn't share this trait is answer d: NaCl.
They only tested two to have a solid hypothesis you need a larger group.
Answer:
Arthroplasty
Explanation:
The restoration of function of a joint is called Arthroplasty. The bone functions are restored by maintaining the bones through resurfacing. Some times artificial joints are also used instead of resurfacing the existing bones.
Arthroplasty is a method to cure Osteoarthritis, or degenerative joint disease where joint cartilages reduces with age.
Also when medical treatments no longer make any impact on the joints of bone pain then Arthroplasty is done.
