Answer:B,C,D
Explanation:
Thermodynamic efficiency is given by
efficiency can be increased by Keeping 
constant and increasing 
Keeping constant and decreasing 
by increasing 
by decreasing 
ratio
2NO2 means that there is 2 oxygen atoms and one nitrogen with two sets of that. So its the third one
Answer:
When you are running the most important force that you should understand is friction. Friction is a force that opposes movement between two objects, but for runners friction makes you faster. Friction gives you a better and more efficient way to use your energy into speed.
<span>D. Atoms of all elements contain protons, but the number of protons is different for every element.
</span>
25 x 10^-5
= 0.00025
25 cm
= 0.00025 km
