What is the gap between two neurons called?

Which of the following statements is correct about receptors?

Which system facilitates the communication between the central nervous system and other parts of the body?

Which of the following statements are true?
$(i)$ Sudden action in response to something in the environment is called reflex action.
$(ii)$ Sensory neurons carry signals from spinal cord to muscles.
$(iii)$ Motor neurons carry signals from receptors to spinal cord.
$(iv)$ The path through which signals are transmitted from a receptor to a muscle or a gland is called reflex arc.

The junction between two neurons is called:

Which of the following statements are true about the brain?
$(i)$ The main thinking part of the brain is the hindbrain.
$(ii)$ Centres of hearing,smell,memory,sight,etc.,are located in the forebrain.
$(iii)$ Involuntary actions like salivation,vomiting,and blood pressure are controlled by the medulla in the hindbrain.
$(iv)$ The cerebellum does not control posture and balance of the body.