To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
Answer:
Giraffes usually only have a single baby, born after a 15-month gestation period. But because they're able to breed all year round, giraffes don't need to 'resynchronise' with the seasons each time they give birth. Sadly, about 50% of giraffe calves do not survive their first year.
Explanation:
Hope this will help
C...the key is that they are photosynthetic...so they produce oxygen (like plants)!
Https://www.ncbi.nlm.nih.gov/books/NBK10039/
Answer:
Longitude and latitude divide the Earth into four (4) Hemispheres.
