求助3道英语单选题,
1.Many new___will be opened up in the future for those with a university degree.
A.realities B.necessaries C.opportunities D.probabilities
2.It's always been the___of our firm to encourage workers to take part in social activities.
A.campaign B.policy C.procedure D.recreation
3.John and Mary,___sure to come to our party this evening.
A.is B.who are C.be D.are