Once _____ , the machine will keep running.
#94334
A
start
B
started
C
to start
D
starting
推荐题目
_______ a chance, we are bound to visit the 2010 Shanghai EXPO. 
#97138
A
To be given
B
Given
C
Giving
D
Having given
______ twice, the postman refused to deliver our letters unless we chained our dog.
#95354
A
Being bitten
B
Bitten
C
Having bitten
D
To be bitten
---Why was the young lady taken away by the police?---- She happened _______ something in the supermarket. 
#94169
A
to catch stealing
B
to catch to steal
C
to be caught stealing
D
to be caught to steal