The frequency will not change
<span>A boat would
produce the highest concentration of carbon monoxide in the exhaust system.
</span>Carbon monoxide<span> (CO) is a colorless, odorless, and tasteless gas that is
slightly less dense than air. It is toxic to </span>hemoglobic<span> <span>animals (both </span></span>invertebrate<span> <span>and
vertebrate, including humans) when encountered in concentrations above about 35 </span></span>ppm<span>.</span>
The answer is D, because the collision's between molecules are elastic, not inelastic.
The heart rate will likely decrease. As the cardiac muscle, or heart, gets stronger, it takes less effort to pump more blood. As a result, the heart will probably beat less, decreasing the heart rate. This is why athletes often have lower heart rates than the average person.
A. is the answer for this question