The answer is above but I don't know if it's correct.
C.) cool feet walking across a hot pavement.
The reason because the other ones deals with radiation. Only C.) is the right answer because the feet is touching the hot pavement which is conduction.
Answer:
Alveoli
The bronchioles end in tiny air sacs called alveoli, where oxygen is transferred from the inhaled air to the blood.
Hope this helps :)
Answer:
Distance will be 49.34 m
Explanation:
We have given wavelength 
Diameter of the antenna d = 2.7 m
Range L = 7.8 km = 7800 m
We have to find the smallest distance hat two speedboats can be from each other and still be resolved as two separate objects D
We know that distance is given by 
So distance D will be 49.34 m