Why are antibiotics not effective for viral diseases?

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

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.

We should not allow mosquitoes to breed in our surroundings because they

Why is $DPT$ called a Triple antigen?

Health is not merely the absence of disease. How can we define health? Classify diseases on the basis of:
$(i)$ Duration of the diseases:
$(ii)$ Cause of the diseases. Give one example of each type.