Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
уч_биолог II.doc
Скачиваний:
57
Добавлен:
18.04.2015
Размер:
641.54 Кб
Скачать

11. In the texts below, fill in the blanks with "male(s)" or "female(s)". The singing humpback whale

A. When a ... Humpback reaches the breeding areas off the east and west coasts of Australia, it sings a song which lasts from six to 35 minutes and may be heard underwater up to 185 kilometres away. All ... in an area sing the same song. The song changes from season to season. ... gather around ... to compete for their attention and leap from the water and roll in mid-air. After mating, the whales migrate to the Antarctic and spend three to four months feeding on krill, then swim north again. A ... gives birth just under 12 months

after mating. The young one suckles for seven months and stays with its mother for up to three years.

B. The Australian Brush-turkey lives in forest. The ... defends a mound and will only allow a ... onto it to lay an egg when he considers the internal temperature is suitable. She may lay in several mounds in an area.

С. Emus move from place to place according to the availability of their plant and insect food. The ... courts the ... , mates with him, then lays up to 15 green eggs. During the 55 days during which the ... incubates, he does not eat, drink nor defecate. The young feed themselves, and stay with the ... for up to 6 months.

12. The paragraphs below are mixed up. Join the paragraphs so as to get a whole text. Begin with paragraph 2.

1. Dolphins are small, torpedo-shaped, toothed cetaceans, which catch fish and other prey using between 100 and 200 sharply pointed teeth.

2. Dolphins, porpoises and whales make up a group called cetaceans ("whale-like animals"), which spend their whole lives in the sea.

3. Dolphins use their own form of echolocation to find out about their surroundings and to locate fish, squid and other prey.

4. Dolphins are highly social and intelligent mammals, which seem to enjoy the company of humans.

5. At the top of the head is a single nostril or blow hole. In the forehead of most species is a fatty, oil-filled "melon", used in echolocation.

6. Dolphins are sociable creatures which often live in groups called pods. They communicate with each other, using high-pitched whistles.

7. There are many stories of dolphins, "helping" distressed human swimmers (if a dolphin is injured, others of its pod will support it and lift it to the surface so it can breathe).

13. Read the text and match the titles with the paragraphs:

Gum leaf gourmet.

At home up in the gum trees.

A Koala grows up.

A very restricted diet.

Koala.

(1) During the 19th and early 20th centuries, millions of Koalas were killed and their skins exported. The Koala became scarce in some areas, extinct in others. Today, the Koala is a general favourite with Australians and a prime attraction for overseas tourists and energetic efforts are being made to conserve it.

(2) Since the species depends on a limited number of species of eucalypt trees for food, preserving adequate numbers of wild Koalas depends on preserving their habitat.

Fossil evidence shows that Koala ancestors lived in rainforests. However, as Australia became drier, the Koala adapted to eat the leaves of the eucalypt trees which replaced much of the rainforests.

(3) A Koala carefully selects a leaf, nips it off, then grinds it up with its molar teeth before swallowing it. The toxic substances which exist in eucalypt leaves are filtered from the Koala's blood by its liver and finally are excreted in its urine. Tiny micro-organisms in the Koala's lengthy caecum ferment the eucalypt leaf fiber and allow the Koala to use the carbohydrates (starches and sugars) it contains. The adult Koala eats for around hours each day and sleeps for just under 20 hours. The remaining one per cent of a Koala's time is used for climbing, changing trees or finding a mate.

(4) A newborn Koala is bee-sized; it weighs about half a gram and is less than 2 cm long. It stays attached to the nipple for 13 weeks and its eyes open at around 22 weeks. The baby's gut acquires the micro-organisms needed to break down leaves when it eats special droppings called "pap" produced by its mother and its teeth appear when it is about 24 weeks old. It will remain in the pouch for another month and be independ­ent of its mother at about one year of age.

(5) A Koala relies on its thick fur to protect it from the weather. It curls into a ball to keep warm or spreads its body out to keep cool. Dark fur on its back absorbs heat, while the lighter fur of its underside reflects heat.

A Koala is well-adapted for life in the branches. It has long limbs and paws with rough pads and sharp claws. Each front paw has two "thumbs", which are opposable to the other three "fingers". The hind feet grip the trunk and support the Koala as its front limbs reach for another hold. The second and third toes are fused and used for grooming. The tail is very reduced.