__________theconvenienceofdigitalpayment,manyseniorcitizensstartedtousesmartphones.
Thefactthatsomanypeoplestillsmokeinpublicplace_______thatwemayneedantionwidecampaigntoraiseawarenessoftheriksofsmoking.
Favorable policies are ___________ to encourage employees' professional development.
Between the two parts of the concert is an interval, __________ the audience can buy ice-cream.