将3cm长的线段AB向下平移4cm得到线段CD,则线段CD的长度为( )cm。
3
______ has been announced, we shall have the singing competition next month.
A.That
B.As
C.It
D.What
I don’t think you can work out the maths problem____her help.
A.since
B.unless
C.with
D.without