老龄化既是挑战也是机遇
Appearance

Zoology is the study of animal life. Works held here relate to animals, animal behaviour, animal life and the different species of animal.
Examples: Earth-Worms and their Wonderful Works (William Henry Larrabee, 1882) ? How Much Animals Know (Frederik Atherton Fernald, 1883) ? The Life of the Spider (Jean-Henri Fabre, 1912)
Child portals: Birds ? Insects (Index Librorum Haliday) ? Mammals