Thevisitingministerexpressedhissatisfactionwiththetalks,________thathehadenjoyedhisstayhere.
C
此处所填的词与其后的宾语从句构成状语，表示伴随情景。 add 是及物动词(有自己的宾语从句)，此处 adding表示主动意义，所表示的动作与谓语动作同时发生。
______alittleearlier,Iwouldhavecaughtthetrain.
Awell-knownexampleofthelargescaledestructionofanecosystemthroughvegetationremovaltoaccommodatetouristfacilitiesisthecaseofthe_______.
Scientistsdoubtwhetherit’s________toregulateone’sbiologicalclockbydrinking.
Asforfamilyeducation,parentsareencouragedtorelyon________ratherthanpunishment.
InEurope_______arethetwoleadingcontendersforaglobalreservationssystem.