Question 18: a
question 19: b
question 20: c
Answer:
At a sunny day at the beach, the top of the sand is warm. The radiation from the Sun heats up the surface of the sand, but sand has a low thermal conductivity, so this energy stays at the surface of the sand.
Answer: i really don't know bu i recomened you watch josie b asmr she is the best
Explanation: