Answer，halfanhour。Explanation，Halfanhourisanexpressionusedtodenoteaperiodoftimeequivalenttothirtyminutes。Expansion，Thisexpressioniscommonlyusedineverydaylife，suchaswhenmakinganappointmentwithadoctororanappointmentwithafriend。Itcanalsobeusedtorefertotheamountoftimeonetakestocompleteatask。Forexample，Itonlytookmehalfanhourtodomyhomework。