Adapted from “Greenhouses: Their Construction and Equipment” by W.J. Wright (1917)

“Generally speaking, there are only two satisfactory methods of greenhouse heating: Steam and hot water. Direct heating by stoves is not satisfactory even in small houses, and no satisfactory system has yet been devised for the use of hot-air furnaces. The only method aside from steam or hot water which deserves mention is heating by flues. (A)

(B) The principles pertaining to greenhouse heating are much the same as those involved in heating other buildings, except that the loss of heat is greater from glass than from wood or brick walls, and a higher and more constant night temperature is required than is necessary in dwellings. For this reason, relatively more radiating surface is required and boilers of larger capacity are needed.

In heating with flues the equipment consists simply of a furnace at one end of the house and a chimney at the other, the two being connected by a flue, carried underneath the bench or buried just underneath the soil, through which the heat and smoke are carried. (C) This may be made of brick, but large-size drain or sewer tile are more commonly used. These withstand the heat and are easily and cheaply put in place. It is best to have the flue slope upward slightly toward the chimney. As has already been stated, this method is wasteful of fuel. It is also difficult to regulate. (D) It is still employed to some extent by gardeners in cheap houses, used only in late winter or early spring for the starting of early vegetable plants, sweet potatoes, etc.”

The following sentence is missing from the passage:

"They are wasteful of fuel, and their use is not justified, except in cheaply constructed houses which are used only for a few months in the spring or fall."

Where would this sentence best fit?

Adapted from “Trees Worth Knowing” by Julia Ellen Rogers (1922)

“The swift unfolding of the leaves in spring is always a miracle. One day the budded twigs are still wrapped in the deep sleep of winter. (A) A trace of green appears about the edges of the bud scales—they loosen and fall, and the tender green shoot looks timidly out and begins to unfold its crumpled leaves. Soon the delicate blade broadens and takes on the texture and familiar appearance of the grown-up leaf. Behold! While we watched the single shoot the bare tree has clothed itself in the green canopy of summer.

How can this miracle take place? How does the tree come into full leaf, sometimes within a fraction of a week? (B)

What is a bud? (C) It is a shoot in miniature—its leaves or flowers, or both, formed with wondrous completeness in the previous summer. About its base are crowded leaved so hardened and overlapped as to cover and protect the tender shoot. (D) All the tree can ever express of beauty or of energy comes out of these precious little ‘growing points,’ wrapped up all winter, but impatient, as spring approaches, to accept the invitation of the south wind and sun.”

The following sentence is missing from the passage:

"It could never happen except for the store of concentrated food that the sap dissolves in spring and carries to the buds, and for the remarkable activity of the cambium cells within the buds."

Where would the sentence best fit?

Adapted from “Another Hardy Garden Book” by Helena Rutherfurd Ely (1915)

“When fruit trees blossom in late April and early May, the whole country where we live becomes, from the many orchards on all sides, one great garden. (A) The exquisite pink-tinged apple blossoms, the pale pink blooms of the peach, the masses of delicate color set in the tender green of budding leaves and fresh grass, all breathing the fragrance of the Spring, make the scene one of beauty indescribable. (B) We can understand and sympathize with the Japanese in their love of the cherry, peach, and plum blossoms, and envy them the life that makes it possible to lay work aside for a time every day and flock to the gardens, where the cult of the fruit tree and the Wistaria, of Pæonies, Lilies, and Chrysanthemums have been brought to perfection, and where they may steep their senses in this beauty daily, from the time the early cherry blossoms come until the petals of the last Chrysanthemum have been borne away by the winds. (C) But how few dwellers in our cities give thought to the wonderful beauty to be seen, just a little way out in the country, when the blossoms come in Spring! (D) To them, living is such a tread-mill of obligation and toil and work, that many go through life with unseeing eyes for the great beauties of Nature. From the days when the stern Pilgrims, hoe in hand and musket slung over the shoulder, wrested a scanty living from the wilderness, until to-day, when millionaires travel between their country places and Wall Street by automobile, swift yacht, or special train, reading the latest edition of the newspaper en route, we have been so occupied in the pursuit of the practical, that as a people we have neglected the cultivation of the sense of love and beauty.”

The following sentence is missing from the passage:

"And even were time available, how few among the multitude would leave the asphalt for a day merely to gaze upon the fairy-like scene!"

Where would the sentence best fit?