(2013·南昌10所省重点中学二模)Mary ________ as a secretary in this company for twenty years and now she stays at home taking care of her own garden.
#99599
A
has served
B
had served
C
is serving
D
served
推荐题目
Yangzhou high school ___________ since 1902. 
#100008
A
has come into existence
B
has been existed
C
has been in existence
D
began to exist
A local radio station said that several eruptions _____ in the past twenty years.
#101916
A
had been taken place
B
took place
C
have taken place
D
had taken place
We________on this project for four hours.Let's have a rest.
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A
are working
B
have been working
C
worked
D
had worked