Before the first nonstop flight made in 1949,it______necessary for all planes to land for refueling.
#104556
A
would be
B
has been
C
had been
D
would have been
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Tom with his friends ______ volleyball since three o’clock.
#103826
A
has been playing
B
is playing
C
have been playing
D
have played
 we_______a film next week.
#101681
A
would see
B
see
C
are seeing
D
are to be seen