Listen! The bird    in the tree.
#40584
A
sing
B
singing
C
is singing
D
is sing.
推荐题目
Help! Tom ________ an accident.
#41602
A
will have
B
has had
C
was having
D
had had
He looks very tired because he           well last night.
#39894
A
didn’t sleep
B
hasn’t slept
C
slept
D
sleeps
When I got to the cinema, the film _____ for five minutes.
#63713
A
had begun
B
has been on
C
has begun
D
had been on