It is said in the book that Thomas Edison (1847—1931) ________ the world-leading inventor for sixty years. 
#104751
A
would be
B
has been
C
had been
D
was
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-- Hi, Samantha! When did you arrive in Leeds? --- Last week, I ___________ a different culture since then.
#101020
A
was experiencing
B
will be experiencing
C
have been experiencing
D
had been experiencing
In the past 5 years a great deal of money _____ improving the environment of the school.
#103617
A
is spent
B
has been spent
C
was spent
D
had been spent
How the fire in the dancing hall started _________ a mystery.
#100979
A
to remain
B
remains
C
is remaining
D
is remained