Container which is heated
Explanation:
substance Q could be <em><u>oxygen (O2)</u></em>
substance R could be <em><u>carbon</u></em><em><u> </u></em><em><u>d</u></em><em><u>i</u></em><em><u>o</u></em><em><u>x</u></em><em><u>i</u></em><em><u>d</u></em><em><u>e</u></em><em><u> </u></em><em><u>(</u></em><em><u>C</u></em><em><u>O</u></em><em><u>2</u></em><em><u>)</u></em>
HM, I think the answer would be D. This is just a guess, so please use it if ou want to answer D it's ok :D
Answer:
The porpoise would hear its echo first because sound travels faster in water than in air. The bat would hear its echo first because the amplitude of sound waves ...
Explanation: