In the last ten years, they _______ three great scientific experiments. 
#103919
A
finished
B
have finished
C
had finished
D
have been finished
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My parents have promised to come to see me before I ____for Africa.
#102732
A
have left
B
leave
C
left
D
will leave
Michael __________ here to see you and he____________ a note on your desk.
#104817
A
has come; had left
B
has been; has left
C
has come; left
D
has been; left
Danny _____ hard for long to realize his dream and now he is popular.
#103778
A
works
B
is working
C
has worked
D
worked