Match each of these parts of body (a-d) to an animal from the box

a) feathers, beak, wings:... c) whiskers, paws, fur:...

b) gills, scales, fin:... d) hooves, tail, mane:...

3.21 Read the text and find the main differences on the three kinds of mammals.

Monotremes lay soft-shelled eggs. The tiny young which hatches from a monotreme egg is naked, blind and has undeveloped hindlimbs. It uses its forelimbs to drag itself to its mother's belly, where it suckles on a patch where milk oozes onto the skin. The Short-beaked Echidna has a pouch, the Platypus does not.

Marsupials give birth to tiny young which are naked, blind and have undeveloped hindlimbs. The baby uses its forelimbs to drag itself to one of its mother's nipples, where it attaches itself. Here, it suckles milk and completes its development. It may be protected by a pouch, or by folds of skin.

Placental mammals keep their young ones inside their bodies until they are well-developed. This is possible because a placenta links the blood vessels of mother and baby and pre­vents the mother's body from rejecting the baby. Once born, the baby suckles milk from its mother's nipples when it is hungry.

Grammar: The Gerund

Герундий – это неличная форма глагола с окончанием ing. Герундий имеет свойства глагола и существительного.