Question

your speech cannot heard by audience _________________ you use powerful mike conjunction.(till)or(unless)

Answer 1

Unless

THIS IS THE RIGHT ANSWER

Answer 2

Your speech cannot be heard by the audience$unless$you use powerful Mike conjunction.

$\bold{What \: is \: a \: Conjunction?}$

A word that joins two or more sentences is called as a conjunction.

$\bold{Types \: of \: Conjunctions}$

↪Coordinating conjunction.

↪Subordinating conjunction

↪Correlative conjunction.