<span>The best
medicine for the constriction of the vessels rod from brain is caffeine.
Caffeine can be found in various foods and drinks such as coffee,
cocoa, cappuccino, frappuccino, soft/energy drinks, chocolate/energy
bars, cough syrup, and other medications.
Answer: Caffeine</span>
When sound waves hit a solid surface they either reflect, refract, or absorb.
Echo's are caused by the reflection of sound waves.
Cumulative frequency is the right answer
I confused On the question
