Inmostbigcitiesitispossibletohireataxiatamoment’snoticewhentheweatherisgood.Butwhenit’srainingpeoplehaveamuchhardertime____61____(find)one.Oneobviousreasonis____62____manypeoplewhowalkshortdistancesduringgoodweatherprefer____63____(take)ataxiintherain.Sotaxiswilltendtobemorefully____64____(occupy)onrainydays.Butthesupplyofavailabletaxisisalsosmallerbecausetaxidriverworksshorterhourswhenitrains.Why?Manydriversaccordingtoarecentsurveyworkonlyaslongas____65____takestoreachatargetedincomeeachday.Onsunnydaystheymustspendmuchoftheirdayforfares____66____ittakeslongertoreachthetarget.Theycanreachthetarget____67____(quick)whenit’srainingbecausetaxistendtobefullmostofthetime.Howeverthecostofgoinghomeseveralhourssooner____68____(be)muchloweronsunnydays.Taxidriversshouldworkasmany____69____(hour)aspossibleonrainydaysandtakemoretimeonsunnydaysiftheirgoalsweretoreachatargetlevelofincomeoveralongerperiodsayonemonthby____70____ (work)thesmallestpossiblenumberofhours.