Answer:
D.) Oxygen-poor
Explanation:
The pulmonary veins are the vessels that carry the oxygen-rich blood to the left atrium
Green plants, mice, snake, and hawk.
True, sleep problems indeed are a quite often occurence among children as well as adults - they do occur quite often but don't necessarily occur all the time for people to whom it does happen. At the same time, when someone suffers from sleep problems, this doesn't necessarily mean that he cannot sleep at all.
The Answer is A haptically
Hope this helps you!!