Infection of pneumonia occurs due to

For which of the following diseases have antibiotics been discovered?

Assertion: $Escherichia$ $coli$,$Shigella$ $sp.$ and $Salmonella$ $sp.$ are all responsible for diarrhoeal diseases.
Reason: Dehydration is common to all types of diarrhoeal diseases and adequate supply of fluids and electrolytes should be ensured.

Pneumonia and common cold are . . . . . . diseases.

In which disease do the liver and spleen become enlarged?

Which one of the following causes plague?