The Earth's Layers Each layer of the Earth is different from the other layers in temperature, density, and composition. The crust is the outer layer and is relatively thin and rocky. It is made up of silicon, aluminum, calcium, sodium, and potassium. The next layer below the crust is the mantle. The mantle is a thick layer of hot liquid rock called magma. The mantle is mainly composed of silicon, oxygen, magnesium, iron, aluminum, and calcium, and it is about 1,800 miles thick. The core of the Earth is divided into the inner and outer core. The outer core is made of extremely hot liquid iron and nickel. It is about 1,425 miles thick. The inner core is composed of an incredibly hot solid iron-nickel core. The inner core remains solid because it is under such extreme pressure. It is about 750 miles in radius. The inner core may have a temperature up to about 13,000°F, which is hotter than the surface of the Sun.
6
Which of the following makes the best introductory sentence?
A.
The Earth is a giant sphere composed of four main layers: the crust, the mantle, the outer core, and the inner core.
B.
Geologists use seismic waves to study the Earth's layers and draw conclusions about the Earth's core.
C.
Scientists believe that the core of the Earth is much denser than the rest of the planet.
D.
The crust of the Earth is thickest under mountains and is thinnest at the ocean floor.

In this excerpt from "quality" by john galsworthy, which two parts clearly indicate the literary point of view of the essay? that tenement had a certain quiet distinction; there was no sign upon its face that he made for any of the royal family—merely his own german name of gessler brothers; and in the window a few pairs of boots. i remember that it always troubled me to account for those unvarying boots in the window, for he made only what was ordered, reaching nothing down, and it seemed so inconceivable that what he made could ever have failed to fit. had he bought them to put there? that, too, seemed inconceivable. he would never have tolerated in his house leather on which he had not worked himself. besides, they were too beautiful—the pair of pumps, so inexpressibly slim, the patent leathers with cloth tops, making water come into one's mouth, the tall brown riding boots with marvellous sooty glow, as if, though new, they had been worn a hundred years. those pairs could only have been made by one who saw before him the soul of boot—so truly were they prototypes incarnating the very spirit of all foot-gear. these thoughts, of course, came to me later, though even when i was promoted to him, at the age of perhaps fourteen, some inkling haunted me of the dignity of himself and brother. for to make boots—such boots as he made—seemed to me then, and still seems to me, mysterious and wonderful.