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
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Unfortunately when we arrived she ___, So we only had time for a few words.
#103021
A
just left
B
has just left
C
was just leaving
D
had just left
---What’s wrong with you, Mr. Keller? --- I’ve had a very bad headache for two days. At first, I ______ I caught a cold, but the medicine ______.
#102841
A
thought, hasn’t worked
B
had thought, didn’t work
C
thought, hadn’t worked
D
have thought, hasn’t worked
There______ more than one student who_______ late this morning.
#103521
A
have been, was
B
has been, were
C
were, was
D
was, was
It seems that oil______from this pipe for some time.We’ll have to take the machine apart to put it right.
#104361
A
had leaked
B
is leaking
C
leaked
D
has been leaking