Theywrotealetterofthanksto________hadhelpedthem.
______,weareairmailingyouourlatestquotation-sheet.
Awell-knownexampleofthelargescaledestructionofanecosystemthroughvegetationremovaltoaccommodatetouristfacilitiesisthecaseofthe_______.
Touristexpenditureshavedifferenteffectsonadestinationeconomy:salesbyfoodvendorstorestaurantsare_______effect;whiletaxifaresandairlineticketsalesare_______effect.
名词解释：abilloflading
