Answer:
80-100 thousand
Explanation:
There are 25,400,000 nanometers in one inch. A human hair is approximately 80,000- 100,000 nanometers wide.
Answer:
closed circulatory system
Explanation:
The blood is pumped through a closed system of arteries, veins, and capillaries. ... Still, blood can flow backward and the system is only slightly more efficient than the open system of insects. The closed circulatory system has more advantages over the open circulatory system.
