Viruses,which cause hepatitis,are transmitted through

Priya's mother uses iodised salt at home. One day while cooking,Priya asked her mother about iodised salt. She said people who do not use iodised salt suffer from deficiency of iodine which leads to goitre and hypothyroidism.
$(a)$ What are the physical symptoms of goitre and hypothyroidism?
$(b)$ How will you inform others about the importance of iodised salt?
$(c)$ Is iodine a metal or a non-metal?
$(d)$ What are the physical properties of iodine?
$(e)$ What is the difference between iodised salt and normal salt?

Given below are a few situations:
$(i)$ Geeta of Class $IX$ was having a common cold. She sits with Sarika,who also develops the disease.
$(ii)$ Animesh of Class $IX$ shifted to a new residence with his family where a water purification system has not been installed yet. He develops Cholera and Dysentery.

State whether the following statement is true or false:
Antibiotics commonly block biochemical pathways important for bacteria. However,viruses do not use these pathways at all,which is the reason why antibiotics do not work against viral infections.

$(a)$ What is immunisation?
$(b)$ Categorise the following into acute,chronic,infectious,or non-infectious diseases: Typhoid,$TB$,Goitre,Elephantiasis.

$A$ person has lost his power to fight infections. Name the disease the person is suffering from. State the pathogen and modes of transmission of this disease.