Can you give a title to this text? (For GMAT/SAT students,Intermediate-Advanced level)

Changes took place in the men themselves as well as in the ways they lived. As time went on, they made better tools and weapons. Then, too, we begin to find signs of how they started thinking of other things than food and the tools to get it with. We find that they painted on the walls of caves, and decorated their tools; we find that they buried their dead. At about the time when the last great glacier was finally melting away, men in the Near East made the first basic change in human economy. They began to plant grain, and they learned to raise and herd certain animals. This meant that they could store food in granaries and “on the hoof” against the bad times of the year. This first really basic change in man’s way of living has been called the “food-producing revolution.”

By the time it happened, a modern kind of climate was beginning. Men had already grown to look as they do now. Know-how in ways of living had developed and progressed, slowly but surely, up to a point. It was impossible for men to go beyond that point if they only hunted and fished and gathered wild foods. Once the basic change was made--once the food-producing revolution became effective--technology leaped ahead and civilization and written history soon began.

THE CHICKADEE -Academic Reading for GMAT/SAT (Intermediate-Advanced level)

Throughout the winter, bands of small birds visit the orchards and ornamental trees of every village and farm, gleaning dormant insects and their eggs from the twigs and boughs. The best known member and the leader, apparently, of the company is the Chickadee. There are generally about half a dozen of these birds together, possibly the parents and young of the preceding summer. The whole company is rarely in sight at any one time; some are in one tree, some are flying to the next, one perhaps is on the ground. There is a constant interchange of lisping call-notes, which break into excited gurgles, and the familiar tee, dee, dee, dee, when something excites their alarm or curiosity. It is not hard to disturb their composure; they come more easily than almost any other bird to the squeaking sound that bird students make to attract the attention of birds. One fluffy head after other pitches into the tree nearest the performer; then, by short stages, the boldest comes nearer to the strange sight and sound, often within arm's length. When their curiosity is appeased, they return to their examination of the twigs and branches, or, if startled by a sudden movement, they dive into the nearest cover.

Their positions when feeding on slender twigs are extremely graceful, and their agility surprising. When gathering sunflower seeds, of which they are extremely fond, they cling to the under surface of the drooping head and pick till they loosen the seed. Then they fly with it to a branch and hammer it open. A favorite winter food is the berry of the poison ivy. By tying a bone or a piece of suet to the branches of trees near the house, not only Chickadees but other birds as well will be attracted to the spot, and will become regular winter visitors. They are by no means confined, however, to villages and farms. Often as we push through the deep snows of the winter forests, the only sound will be the distant lisp of this hardy bird.

Besides the notes heard so commonly in winter, the Chickadee has a pensive and extremely gentle whistle, which it utters while sitting motionless, and oftener in spring than at other seasons, though it may be heard in every month of the year. It consists of two notes, an exact interval apart, and each accented. It is often mistaken, especially in early spring, for the song of the Phœbe, but it may be distinguished by its purity and sweetness. It is easily imitated by whistling, and the bird will often answer, or even fly toward the person whistling, and survey him with astonishment.

It is generally believed by people who see the bird only in winter that the Chickadees retire northward in spring; it is true that they then no longer frequent the yards and gardens, but in the woods and retired orchards many a pair have excavated some decaying birch or apple stump, and after lining it warmly with moss and feathers, provided amply for the continuance of their race; sometimes as many as nine eggs are laid. In winter, the birds spend the night in holes, not necessarily the same in which they were bred.

Several writers have mentioned instances of the extreme boldness of this bird; Mr. Chapman has had a Chickadee perch on his hand. One can easily imagine it, but we do not need such a mark of confidence to feel strong affection for this companionable and winter-loving bird.

THE HERRING GULL- Academic Reading for GMAT/IELTS/SAT (Intermediate-Advanced level)

All winter, a traveler along the seashore sees the great gray gulls wheeling gracefully through the air with outstretched wings, floating lightly on the water, or sitting in long lines or compact masses on the bars or flats which are exposed at low tide. The harbors of all the northern seacoast cities are visited in winter by numbers of these birds, constantly on the watch for any bits of refuse which may be thrown from the wharfs or vessels, or brought down by the tides or currents. Their long and powerful wings make the flight of even so heavy a bird a sight beautiful to watch, and the water looks deserted when the motion and color which the gulls furnish is absent. But it is not to the eye alone that the birds appeal.

The ceaseless activity of the gulls in pursuit of floating refuse and their inordinate appetite make them invaluable scavengers; without them, the refuse dumped into the water would return at each tide to pollute the shore. No idea can be formed of the value of the service performed by the gulls, till one sees the countless throngs which hover over the dumping grounds in the lower New York Bay, awaiting the arrival of the scows with the refuse from that city. As the buzzards and vultures are protected in all warm countries for their services in devouring carrion, so ought these scavengers of the northern seas to be guarded from persecution.

The adult Herring Gull in full plumage has pure white underparts, head and tail, but a gray mantle, as it is termed, is spread over the wings. Young birds, however, show many shades of brown, and attain the white only after a year or two. The small, elegantly built birds, known along the seacoast as Mackerel Gulls, are not strictly gulls, but terns. They may be known by their forked tails and by their black caps. It is they that hover screaming over the water, constantly darting down to strike at fish.

Gulls breed commonly along the coast of Maine and far northward. Great colonies occupy a small area, and a visit to their breeding places is a marvelous experience. At the approach of an intruder, the parents rise from their nests and circle about overhead, uttering hoarse cries, till the air is full of their wheeling forms. The downy young squat in the grass or bushes till the danger is past.

Both gulls and terns have long been persecuted for their soft white and gray plumage, which is coveted for the adornment of women's hats. As the destruction of the birds on the islands where they are breeding would soon destroy the whole race, efforts are being made by the lovers of birds to protect the birds on all the sandy points or rocky islands where they rear their young.

Gulls have wonderful powers of flight, and some species often follow ocean steamers for days, flying constantly about the vessel's stern, watching for bits of food which may be thrown overboard. When an object is spied the whole flock dart upon it, and it soon disappears among the crowd of struggling birds.

In the Eastern States gulls are always associated with the sea, but in the Mississippi valley certain species are found on the prairies, where they follow the plough to seize the upturned insects.

THE GOLDEN-CROWNED KINGLET GMAT/IELTS/SAT Reading (Intermediate-Advanced level)

The Golden-crowned Kinglet is, next to the Humming-bird, almost our smallest bird, and it frequents thick evergreens so continually that it is rarely seen. There is little in its voice and habits to attract attention, and its activity and restlessness are so constant that we rarely catch sight of the bit of color which it possesses,—the crown which the little king carries. But if we train our ear so that it catches every fine natural sound, no matter how trifling, we become aware some crisp winter day of a thin see, see, see, often repeated from some hedge, or group of orchard trees. If we watch, our eye will catch sight of one or two tiny creatures, flitting restlessly among the twigs, keeping their wings in almost constant motion, even when not actually flying. The general color of the bird is a shade known in the books as olivaceous, but the effect outdoors and at a distance is a dark gray; across the wings there are little whitish bars, and over the head dark lines enclose the little crown,—yellow in the female, orange in the male.

If we succeed in attracting the Chickadees to our trees, by tying up bones, the Kinglets often come in their company, but their little bills are too weak to pick at the frozen gristle, and they merely glean from the twigs and buds. The little scale insects, the eggs of moths and spiders, all manner of minute objects, are detected by their sharp eyes and seized by their skillful little bills and tongues. At night, the band retires to some thick evergreen hedge or grove, ready the next morning to resume their busy rounds. In April, the male is moved to utter a simple little song, and by the end of the month the whole company moves to the spruce forests of the North, not to return to us until the next September.

In the Northern States, the Golden-crowned Kinglet is the only species that remains all winter, but from Virginia southward its cousin, the Ruby-crowned Kinglet, is associated with it; in summer, strange to say, the more Southern winter species goes farther North than the Golden-crowned, breeding from northern Maine to the frigid zone. A few years ago, no eggs or nest of either Kinglet had been described, but when they were at last discovered, they proved as dainty as the little builders themselves. The nest is globular, with an entrance in the upper part; it is placed in a thick mass of spruce twigs and composed of hanging moss, ornamented with bits of dead leaves, and lined chiefly with feathers. In such a nest, as many as nine eggs are often laid; imagine the little Golden-crown brooding in this bower. 

Like some of the Warbler family, the Kinglet does not let an insect escape, though it should take wing before it could be seized. The bird, too, has wings, and darts out after its prey. In winter, it often hovers under the piazza roofs, or the lintels of the barn door, and while in the air, picks off the eggs or chrysalides that have been hidden in the crevices. Occasionally one of the birds, in its eagerness to seize some attractive morsel, flies sharply against a windowpane. No doubt it is the part of a thrifty householder to sweep out the insects from his piazza roof, but there are some, like Lowell, wise enough to leave a few decayed limbs on their apple trees for the Woodpeckers, a patch or so of weeds for the Snowbirds, and a chrysalis or two for the hungry Kinglets in winter.

GLACIERS CHANGE THE WEATHER

Great sheets of ice change the weather. When the front of a glacier stood at Milwaukee, the weather must have been bitterly cold in Chicago. The climate of the whole world would have been different, and you can see how animals and men would have been forced to move from one place to another in search of food and warmth.

On the other hand, it looks as if only a minor proportion of the whole Ice Age was really taken up by times of glaciation. In between came the interglacial periods. During these times the climate around Chicago was as warm as it is now, and sometimes even warmer. It may interest you to know that the last great glacier melted away less than 10,000 years ago. Professor Ernst Antevs thinks we may be living in an interglacial period and that the Ice Age may not be over yet. So if you want to make a killing in real estate for your several hundred times great-grandchildren, you might buy some land in the Arizona desert or the Sahara.

We do not yet know just why the glaciers appeared and disappeared, as they did. It surely had something to do with an increase in rainfall and a fall in temperature. It probably also had to do with a general tendency for the land to rise at the beginning of the Pleistocene. We know there was some mountain-building at that time. Hence, rain-bearing winds nourished the rising and cooler uplands with snow. An increase in all three of these factors--if they came together--would only have needed to be slight. But exactly why this happened we do not know.

The reason I tell you about the glaciers is simply to remind you of the changing world in which prehistoric men lived. Their surroundings--the animals and plants they used for food and the weather they had to protect themselves from--were always changing. On the other hand, this change happened over so long a period of time and was so slow that individual people could not have noticed it. Glaciers, about which they probably knew nothing, moved in hundreds of miles to the north of them.

The people must simply have wandered ever more southward in search of the plants and animals on which they lived. Or some men may have stayed where they were and learned to hunt different animals and eat different foods. Prehistoric men had to keep adapting themselves to new environments and those who were most adaptive were most successful.