A.Cries of birds are affected by seasons.B.Only some sorts of birds can cry.C.Birds would cry when they meet dangers.D.It is easy to tell the singing of a bird from its crying.
A.Cries of birds are affected by seasons.
B.Only some sorts of birds can cry.
C.Birds would cry when they meet dangers.
D.It is easy to tell the singing of a bird from its crying.