下图①、②、③、④中,能正确反映世界人口增长的是( )
A:①
B:②
C:③
D:④
The man in black must be Lily's brother.(改为否定句)
The man in black ____ ____ Lily's brother.
若集合P=0,x,Q=1,2,P∩Q=2,则P∪Q=( )