Hi, Bob. ____ is my new friend, Mary. -–Nice to meet you, Mary.

The meeting was concerned _____ reforms and everyone present was concerned _____ their own interests[ ]

When shall I call , in the morning or afternoon — . I’ll be in all day

Are you collecting （收集） any old warm clothes—Yes, we will to the poor students in a village school．

The police tried to get some clues from the suspect, but he remained______.