--I hear this kind of CD-ROM is very pop
问题:
--I hear this kind of CD-ROM is very popular.
--Let’s buy one before it ____________.
A.is come out
B.comes out
C.sells out
D.is sold out
--I hear this kind of CD-ROM is very popular.
--Let’s buy one before it ____________.
A.is come out
B.comes out
C.sells out
D.is sold out