Brody and Ethel are arguing about waves. Brody says that waving his hand back and forth is a scientific wave. Ethel says that it is not. Which statement best describes who is correct? Brody is correct because the wave involves an input of energy.
Ethel is correct because energy is not carried from one place to another.
Brody is correct because the pattern repeats.
Ethel is correct because the motion has no pattern.

chordata is the answer

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

coal is not sustainable because it will one day run out.