Cholera, leprosy, and diphtheria are:

Which of the following acts as a vector for the pathogen of typhoid?

Given below are two statements $:$
Statement-$I$ : Typhoid fever can be confirmed by the Widal test.
Statement-$II$ : Intestinal perforation and death may occur in severe cases of typhoid.
In the light of the above statements,choose the correct answer from the options given below $:$

Penicillin and streptomycin antibiotics are used in the treatment of which disease?

What is the causative agent of plague?

$S -$ Assertion: In typhoid,there is abdominal pain,constipation,and inflammation in the small intestine.
$R -$ Reason: In the diseased condition,$Salmonella$ $typhi$ is found in the human intestinal tract.