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.
(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.
14. Read the text and choose the most suitable heading from the list a-c for each part 1 – 3 of the text.
c. The world’s famous classification.
1. Every animal is known by two sorts of names. The scientific name, which is made from Latin or Greek words, remains the same all over the world. The first word of a scientific name places the animal in a genus with other animals, closely related to it. The second word is the animal's species.
The common name varies from country to country according to the language spoken. The common name of a species uses capital letters, e.g. Red Kangaroo. However, the common name of a group of animals, such as kangaroos, takes a lower-case letter.
2. Unlike domestic dogs, the female Dingo has only one breeding cycle per year, and a Dingo's teeth and skull differ from those of domestic dogs. Its most likely ancestor is the Indian Plains Wolf.
Dingos live in a well-defined home range, which may be shared with others. Individuals hunt small game on their own, but join to take larger prey. A group may consist of a breeding pair and younger animals. Dingos interbreed with domestic dogs.
3. Worldwide, there are about 8,800 species of living birds. Over 760 species of birds have been recorded from Australia and the oceans nearby.
A bird's plumage may account for up to 15% of its total weight, its skeleton only 5%.
Most birds have 1,500 to 3,000 feathers. A swan has up to 25,216. The protein of which feathers are made is also found in lizard skin.
The fastest flying birds can reach speeds in excess of 20 meters per second. Small birds on migration may cover 1,000 kilometers non-stop in 24 hours.