Question

________ have valves in them
options:-
(physical, oxygen, veins, arteries, salts, sugar)
​

Answer 1

:

Veins carry the blood back to the heart. ... Unlike arteries, veins contain valves that ensure blood flows in only one direction. (Arteries don't require valves because pressure from the heart is so strong that blood is only able to flow in one direction.)

Answer 2

Answer:

veins have valves in thwm