Answer: The answer is B.Sonar and C.Radar
Explanation:
They are both just like an echo which is the main things that uses reflected sound waves. They are basically like synonyms for echo.
Answer:
C
Explanation:
C. The electronegativity value of calcium is lower than the electronegativity value of silicon
is the only correct statement.
Answer: Peer-reviewed journal article is the most useful because the information in them had been carefully scrutinized and aproved by people who are experts in that particular field.
Yes they can have origins in nature. A bunch of the elements on the periodic table are chemicals and this are basic substances and cannot be man made.
