The United States: O uses almost 25% of the world's energy
O is the leading supplier of fossil fuels
O is the most populous country in the world
O designed and launched the Mir Space Station

the answer is d. chordata

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

the answer is "a.) well–developed vascular system."

explanation: