Ten is your answer I think
Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
The energy of the sun of course :3
Answer:
results could be biased and therefore they are not reliable
Explanation:
A conflict of interest is generated when the authors of a given study have any type of interest that could influence their judgments, results and/or conclusions. These conflicts of interest include any relevant financial relationships, personal, religious, political or intellectual interests. To solve this situation, peer-reviewed, well-reputed journals generally include a conflict of interest statement where authors declare all interests that might be perceived as conflicting.
