1 . The fire started on the second floor and it wasn't long ______ the whole building was burned down.

A．while	B．when
C．after	D．before

2 . I missed the last bus and had no money for a taxi，so I could do nothing but ____ home last night.

A．to walking	B．walk
C．walking	D．walked

3 . I don’t think this case is _______________

A．great importance	B．of great importance．
C．of very importance	D．of very important

4 . Rather than _____his car on the busy road, Mr Green always prefers____ his bike.

A．drive; to ride	B．driving; ride
C．to drive; riding	D．to drive; ride