What measures should be taken to avoid the transmission of $STD$s?
$I$. Avoid sex with unknown partners
$II$. Avoid sex with multiple partners
$III$. Use protection during sex
$IV$. Avoid sharing needles

Venereal diseases (Sexually Transmitted Infections) can spread through:
$(a)$ Using sterile needles
$(b)$ Transfusion of blood from an infected person
$(c)$ Infected mother to foetus
$(d)$ Kissing
$(e)$ Inheritance
Choose the correct answer from the options given below.

Which of the following principles are used to prevent $STD$ infection?
$(i)$ Avoid sex with unknown partners
$(ii)$ Use condoms during coitus
$(iii)$ Blood transfusion
$(iv)$ All of these

Which of the following principles should be followed to stay free from Sexually Transmitted Infections $(STIs)$?

All reproductive tract infections $(RTIs)$ are $STDs$,but all $STDs$ are not $RTIs$. Justify with an example.

$..........$ are a major threat to a healthy society.