________hard before, Tom is afraid of failing in the exam. 
#97409
A
Having been worked
B
Not to have worked
C
Having never worked
D
Never have worked
推荐题目
As a child, Johnson would sit on the steps alone, _______ the sun ______ down.
#90644
A
watching; go
B
watching; went
C
watched; going
D
watched; went
Five people were reported ________ in the accident.
#95367
A
to be killed  
B
to kill
C
killed    
D
to have been killed
The time he has devoted in the past years ________ the disabled is now considered _______of   great value.
#92923
A
to help; being
B
to help; to be
C
to helping; to be
D
helping; /
We agreed _______ here but so far she hasn’t turned up yet. 
#98624
A
having met
B
meeting
C
to meet
D
to have met