It is essential that these application forms( )back as early as possible.
A.正确答案Dmust be sent
B.are sent
C.will be sent
D.be sent
It is essential that these application forms( )back as early as possible.
It is essential that these application forms( )back as early as possible.
A.正确答案Dmust be sent
B.are sent
C.will be sent
D.be sent