—My dad bought me a new MP4, but I don't know ____.
--Let's read the instructions.
A.what to use B.which one to use
C.how to use it D.when to use it
—My dad bought me a new MP4, but I don't know ____.
--Let's read the instructions.
A.what to use B.which one to use
C.how to use it D.when to use it
C