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. 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.

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. 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. 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.”

Which of the following best describes the purpose of this passage?

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 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? 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.

What is a bud? 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. 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.”

What is the purpose of the passage?