Which of the following is true about renewable resources?

a. they can be replaced by a healthy environment.

b. there are plenty for people to use, but only for a very short time.

c. using them will hurt the environment.

d. they cannot be replaced after they are used up.

Neurotransmitters are messengers responsible for communication between neurons. they are released from synaptic vesicles and are received by receptors.  the communication is referred to as neurotransmission. the following statement is true about neurotransmitters: a. they're stored in synaptic vesicles in the axon.