-Has Tommy finished his homework yet?-I have no idea; he ____ it this morning.
#104683
A
was doing
B
had been doing
C
has done
D
did
推荐题目
If nothing______, the oceans will turn into fish deserts. 
#99587
A
does
B
had been done
C
will do
D
is done
Food supplies in the flood-stricken area _______. We must act immediately before there’s none left.
#100781
A
have run out
B
have been run out
C
are running out
D
are being run out