Answer:
The correct answer is A
Explanation:
To avoid complications during surgery, patients should have adequate blood volume, if the donates blood in a week and is operated on in 2 months, there should be a prudent time, for hematopoiesis, to compensate for the donated.
The mother contributes 50% to the child, and the father contributes the other 50% to make up the full 100% of the child's genes.
Vertebral arch is the correct answer
