77. --- Have all the important letters been delivered at the first time?
--- I’m sorry. _______ only 40% of them.
A.It is
B.They are
C.There are
D.It has been
A
77. --- Have all the important letters been delivered at the first time?
--- I’m sorry. _______ only 40% of them.
A.It is
B.They are
C.There are
D.It has been
A