Question

veins and arteries are both blood vessels in the circulatory system. however, their anatomies and functions are quite different. arteries carry oxygen - rich blood away from the heart to other parts of the body, while veins carry low - oxygen blood back to the lungs and heart. most arteries are located deep within the body. they are made up of thick muscle layers that can handle the high pressure of blood flow, and they usually appear red. by contrast, veins are composed of thin muscle layers. both veins and arteries have a hollow space called the lumen through which the blood can travel. veins can be found deep in the body or close to the skin, and they usually look blue. the blood in veins moves under very low pressure. unlike arteries, veins have valves that keep the blood flowing in the right direction.
veins arteries
are blood vessels
carry blood to the heart
made of thick muscle layers
appear blue
have valves

Explanation:

Veins and arteries are blood - vessels. Veins carry blood to the heart, are made of thin muscle layers, appear blue and have valves. Arteries carry blood away from the heart, are made of thick muscle layers and usually appear red.

Answer:

Are blood vessels: Veins - √, Arteries - √
Carry blood to the heart: Veins - √, Arteries - ×
Made of thick muscle layers: Veins - ×, Arteries - √
Appear blue: Veins - √, Arteries - ×
Have valves: Veins - √, Arteries - ×