I am so tired,for I ________ English for 2 hours.
#99761
A
is studying 
B
have been studying
C
was studying 
D
had been studying
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Don’t worry. Your dog _____good care of while you are away on holiday next week. 
#102981
A
will take
B
is taking
C
will be taken
D
.has been taken
Your phone ______ for several minutes now. Why don’t you answer it?
#100562
A
had rung
B
rang
C
has been ringing
D
was ringing
—Sorry. I ________ to post the letter for you. —Never mind. ________ it myself after school. 
#104473
A
forget; I’d rather post
B
forgot; I’ll post
C
forgot; I’m going to post
D
forget; I’d better post
. These old buildings possibly __________ the Ming Dynasty.
#103505
A
dated back to
B
date back to
C
date back
D
are dated back to