(2013·合肥一检)According to the rules and regulations, all payments ________ be made in cash in the shopping center.

____ the police know the killer’s identity, they are getting close to catching him.

It’s so late. Why not write the report tomorrow —But I don’t know _______. I can do it if not now.

The old man lives alone on an island, andhis home is not accessible ______ by boat.

The book in _______ I have much interest now is Around the World in Eighty Days.