If cranial nerves are $12$ pairs, then spinal nerves are: (in $pairs$)

Given below are two statements $:$
Statement-$I$ : The cerebellar hemispheres are connected by a tract of nerve fibres known as the corpus callosum.
Statement-$II$ : The brain stem consists of the midbrain and all parts of the hindbrain.
In the light of the above statements,choose the most appropriate answer from the options given below.

If the human cerebellum is damaged,what happens to the person's movements?

Consider the following statements regarding the human brain:
$1.$ The cerebrum has a highly convoluted surface,which provides space for more neurons.
$2.$ The medulla oblongata is connected to the spinal cord.
$3.$ The medulla oblongata contains centers for respiration,cardiovascular reflexes,and gastric secretions.
Which of the above statements are correct?

The central nervous system develops as a result of

Which part of the brain is affected in a person who consumes alcohol?