A.an expression of happiness | B.a way of warning |
C.an expression of anger | D.a way of greeting |
A.A place where families of other species are not accepted |
B.A place where a bird may shout at the top of its voice |
C.An area for which birds fight against each other |
D.An area which a bird considers to be its own |
A.Because they want to invite more friends |
B.Because their singing helps frighten outsiders away |
C.Because they want to find outsiders around |
D.Because their singing helps get rid of their fears |
A.By comparing birds with human beings |
B.By reporting experiment results |
C.By describing birds daily life |
D.By telling a birds story |