In the past decades, sea ice _____in the Arctic as a result of global warming.
#102142
A
had melted
B
has been melting
C
melted
D
is melting
推荐题目
When we reached the stadium in a rush,  the newly-elected major ____ his speech and the performance _______.
#102284
A
have finished ; began
B
had just finished; was about to begin
C
had just finished; had begun
D
just finished; began
It is when the plane ______ that you’d better find out at the booking office.
#104088
A
would take off
B
had taken off
C
was taking off
D
is taking off
 The little boy is dirty from head to foot because he ______ in the mud all morning.
#103627
A
has played  
B
has been playing
C
is playing 
D
was playing