Evidence would the fossils they left in the grounds they found.
Answer: The answer is the last option, Backflow of blood through a defective valve.
Explanation: Hypotension causes high blood pressure, and the other two options are not related to heart murmurs. A hear murmur is when the blood isn't flowing in the right direction causing the hear to beat irregularaly.
Answer:
Radiation
Explanation:
Radiation is the transfer of heat by means of electromagnetic waves.
The correct answer is option D.
If a girl is standing in front of a smooth surface from which a sound is reflected, the girl may hear two similar sets of sounds if she is also near the source of the sound.
For proper reflection of all sorts of energy waves, a hard flat surface is preferable. This helps to reflect waves without losing energy. Hard and smooth surfaces are best for travelling of sound waves because sound is related to pressure.