Adapted from "How the Soil is Made" by Charles Darwin in Wonders of Earth, Sea, and Sky (1902, ed. Edward Singleton Holden)

Worms have played a more important part in the history of the world than most persons would at first suppose. In almost all humid countries they are extraordinarily numerous, and for their size possess great muscular power. In many parts of England a weight of more than ten tons (10,516 kilograms) of dry earth annually passes through their bodies and is brought to the surface on each acre of land, so that the whole superficial bed of vegetable mould passes through their bodies in the course of every few years. From the collapsing of the old burrows, the mold is in constant though slow movement, and the particles composing it are thus rubbed together. Thus the particles of earth, forming the superficial mold, are subjected to conditions eminently favorable for their decomposition and disintegration. This keeps the surface of the earth perfectly suited to the growth of an abundant array of fruits and vegetables.

Worms are poorly provided with sense-organs, for they cannot be said to see, although they can just distinguish between light and darkness; they are completely deaf, and have only a feeble power of smell; the sense of touch alone is well developed. They can, therefore, learn little about the outside world, and it is surprising that they should exhibit some skill in lining their burrows with their castings and with leaves, and in the case of some species in piling up their castings into tower-like constructions. But it is far more surprising that they should apparently exhibit some degree of intelligence instead of a mere blind, instinctive impulse, in their manner of plugging up the mouths of their burrows. They act in nearly the same manner as would a man, who had to close a cylindrical tube with different kinds of leaves, petioles, triangles of paper, etc., for they commonly seize such objects by their pointed ends. But with thin objects a certain number are drawn in by their broader ends. They do not act in the same unvarying manner in all cases, as do most of the lower animals.

The underlined word “unvarying” most nearly means __________.

Adapted from A Catechism of Familiar Things: Their History and the Events Which Led to Their Discovery by the Benziger Brothers (1881)

Iron is one of the most useful and abundant metals, being found in all mineral earths, stones, plants, and animal fluids. Iron is found in great masses, in various states, in the bowels of the earth; it is usually, however, compounded with stone, from which it is separated by the action of fire. In some parts of the world, whole mountains are formed of iron; among these may be mentioned the Pilot Knob and the Iron Mountain, in Missouri, being unsurpassed by anything of the kind found elsewhere.

It is hard, fusible, not very malleable, but extremely ductile, and very tenacious; it is of a greyish color, and nearly eight times heavier than water. Without iron, society could make no progress in the cultivation of the ground, in mechanical arts or trades, in architecture or navigation; it is therefore of the greatest use to man.

The underlined word “abundant” most nearly means __________.

Adapted from "Life Growth - Frogs" by Margaret Warner Morley in A Book of Natural History (1902, ed. David Starr Jordan)

Our common frogs, like many of the fishes, do not trouble themselves about the fate of their eggs after they are carefully laid in a safe place. They trust Mother Nature to see the little tadpoles safely through the perils of childhood, to help them avoid being eaten or starving, and cut, not their teeth, but their arms and legs.

In Venezuela, however, there dwells a frog with well developed maternal instinct. The mothers have pockets on their backs, not for their own convenience, but as cradles for their babies. The fathers put the fertilized eggs into the pockets of the mothers, and there they remain, well guarded, until the young are able to care for themselves.

The underlined word “perils” most nearly means __________.

Adapted from Anecdotes of the Habits and Instincts of Animals by Mrs. R. Lee (1852)

The Carnivora are divided by naturalists into three groups, the characters of which are taken from their feet and manner of walking. Bears rank among the Plantigrada, or those which put the whole of their feet firmly upon the ground when they walk. They are occasionally cunning and ferocious, but often evince good humor and a great love of fun. In their wild state, they are solitary the greater part of their lives. They climb trees with great facility; live in caverns, holes, and hollow trees; and in cold countries, retire to some sequestered spot during the winter, where they remain concealed and bring forth their young. Some say they are torpid, but this cannot be, for the female bears come from their retreats with cubs that have lived upon them, and it is not likely that they can have reared them and remained without food; they are, however, often very lean and wasted, and the absorption of their generally large portion of fat contributes to their nourishment. The story that they live by sucking their paws is, as may be supposed, a fable; when well-fed they always lick their paws, very often accompanying the action with a peculiar sort of mumbling noise. There are a few which will never eat flesh, and all are able to do without it. They are, generally speaking, large, clumsy, and awkward, possessing large claws for digging, and often walk on their hind feet, a facility afforded them by the peculiar formation of their thigh bone. They do not often attack in the first instance, unless impelled by hunger or danger; they are, however, formidable opponents when excited. In former times, there were few parts of the globe in which they were not to be found, but, like other wild animals, they have disappeared before the advance of man. Still they are found in certain spots from the northern regions of the world to the burning climes of Africa, Asia, and America. The latest date of their appearance in Great Britain was in Scotland during the year 1057.

The underlined word “torpid” most probably means __________.

Adapted from Anecdotes of the Habits and Instincts of Animals by Mrs. R. Lee (1852)

The Carnivora are divided by naturalists into three groups, the characters of which are taken from their feet and manner of walking. Bears rank among the Plantigrada, or those which put the whole of their feet firmly upon the ground when they walk. They are occasionally cunning and ferocious, but often evince good humor and a great love of fun. In their wild state, they are solitary the greater part of their lives. They climb trees with great facility; live in caverns, holes, and hollow trees; and in cold countries, retire to some sequestered spot during the winter, where they remain concealed and bring forth their young. Some say they are torpid, but this cannot be, for the female bears come from their retreats with cubs that have lived upon them, and it is not likely that they can have reared them and remained without food; they are, however, often very lean and wasted, and the absorption of their generally large portion of fat contributes to their nourishment. The story that they live by sucking their paws is, as may be supposed, a fable; when well-fed they always lick their paws, very often accompanying the action with a peculiar sort of mumbling noise. There are a few which will never eat flesh, and all are able to do without it. They are, generally speaking, large, clumsy, and awkward, possessing large claws for digging, and often walk on their hind feet, a facility afforded them by the peculiar formation of their thigh bone. They do not often attack in the first instance, unless impelled by hunger or danger; they are, however, formidable opponents when excited. In former times, there were few parts of the globe in which they were not to be found, but, like other wild animals, they have disappeared before the advance of man. Still they are found in certain spots from the northern regions of the world to the burning climes of Africa, Asia, and America. The latest date of their appearance in Great Britain was in Scotland during the year 1057.

The underlined word “sequestered” most nearly means __________.

Adapted from Cassell’s Natural History by Francis Martin Duncan (1913)

The penguins are a group of birds inhabiting the southern ocean, for the most part passing their lives in the icy waters of the Antarctic seas. Like the ratitae, penguins have lost the power of flight, but the wings are modified into swimming organs and the birds lead an aquatic existence and are scarcely seen on land except in the breeding season. They are curious-looking creatures that appear to have no legs, as the limbs are encased in the skin of the body and the large flat feet are set so far back that the birds waddle along on land in an upright position in a very ridiculous manner, carrying their long narrow flippers held out as if they were arms. When swimming, penguins use their wings as paddles while the feet are used for steering.

Penguins are usually gregarious—in the sea, they swim together in schools, and on land, assemble in great numbers in their rookeries. They are very methodical in their ways, and on leaving the water, the birds always follow well-defined tracks leading to the rookeries, marching with much solemnity one behind the other in soldierly order. 

The largest species of penguins are the king penguin and the emperor penguin, the former being found in Kerguelen Land, the Falklands, and other southern islands, and the latter in Victoria Land and on the pack ice of the Antarctic seas. As they are unaccustomed from the isolation of their haunts to being hunted and persecuted by man, emperor penguins are remarkably fearless, and Antarctic explorers invading their territory have found themselves objects of curiosity rather than fear to the strange birds who followed them about as if they were much astonished at their appearance. 

The emperor penguin lays but a single egg and breeds during the intense cold and darkness of the Antarctic winter. To prevent contact with the frozen snow, the bird places its egg upon its flat webbed feet and crouches down upon it so that it is well covered with the feathers. In spite of this precaution, many eggs do not hatch and the mortality amongst the young chicks is very great.

What can you infer is “the ratitae," underlined in the first paragraph?