Great as Newton was, many of his ideas _______ today and are being modified by the work of scientists of our time.
#102473
A
are to challenge
B
may be challenged
C
have been challenged
D
are challenging
推荐题目
When I got on the bus,I_____I had left my wallet at home.
#102653
A
was realizing
B
realized
C
have realized
D
would realize
He would have gone to visit Linda yesterday, however , he _____on by Linda instead. 
#101972
A
was called
B
called
C
would be called
D
has been called
--Do you know anyone in Paris?    --No, I’ll make friends once______ .
#104171
A
I’m settled  
B
I have settled
C
I’ll be settled
D
I’m settling
I know a little bit about the city as I __________ there for one year in my youth.
#102511
A
am studying
B
had studied
C
studied
D
have studied