Explain a complex idea precisely
Grade 11 Reading Worksheet
Circle the best answer.
Read this first
How a Levee Holds Back a River (student informative essay draft)
[1] A levee is an embankment built along the bank of a river to keep high water inside the channel during a flood, and the idea comes from a landform that rivers build for themselves. [2] When a river overflows, the water spreading across the surrounding floodplain slows down immediately after it leaves the deep, fast-moving channel. [3] Slow water cannot carry as much sediment as fast water, so the coarsest sand settles first, right beside the bank, while finer silt is carried farther out. [4] After many floods, these deposits build a low ridge along each bank, which geologists call a natural levee.
[5] Artificial levees copy this shape on a much larger scale, and most of them are built from earth that has been packed down hard rather than from concrete. [6] The levees along the Mississippi River go on for what seems like forever, protecting towns and farms.
[7] Engineers recognize several distinct ways in which a levee can fail during a prolonged flood. [8] The most obvious is overtopping, in which the river rises higher than the levee and pours over its crest, wearing away the slope on the dry side. [9] A less visible but equally serious danger comes from water traveling through the permeable ground beneath the embankment. [10] The river's weight pushes water through the sand beneath the embankment. [11] Water bubbles up on the dry side, carrying sand with it. [12] Such a spot is called a sand boil, and if it keeps flowing, it can hollow out a channel back toward the river beneath the levee, a process that engineers call piping. [13] Flood crews control a sand boil by stacking a ring of sandbags around it, so that water collects inside the ring and its weight slows the flow from below.
[14] Understanding these dangers explains why levee inspectors patrol the dry side of an embankment during a flood, searching for small bubbling springs as attentively as they monitor the water rising on the river side.
Ari wants one sentence to join [10] and [11] so the reader sees how they relate. Which sentence does that best?
- The river's weight pushes water through the sand beneath the embankment, and water bubbles up on the dry side with some sand in it.
- Because the river's weight pushes water through the sand beneath the embankment, water can bubble up on the dry side, carrying sand with it.
- The sand beneath the embankment, through which the river's weight pushes water that bubbles up on the dry side, is found under many levees around the world.
- Because water bubbles up on the dry side carrying sand, the river's weight pushes water through the sand beneath the embankment.
Bo wants a comparison after [12] to help a reader picture piping. Which comparison fits the process best?
- It is like water spilling over the rim of a bathtub that has been filled too full.
- Piping works much like a trickle through a sandcastle wall: the moving water carries grains away, the hole widens, and the faster flow carries off still more.
- Piping is a quiet trick of nature, mysterious and dramatic, unfolding out of sight beneath the ground where no one can watch it happen.
- Piping resembles the internal erosion of a rock-fill dam's filter zone when its grain-size criteria are not met.
Esme finds [6] too loose for an informative essay. Which revision of [6] meets the norms of the subject best?
- The federal flood-control system on the lower Mississippi River and its tributaries includes a great many miles of levees, which protect a large number of towns and a great deal of farmland.
- You would not believe how many miles of levees line the lower Mississippi River and its tributaries, and they protect a lot of towns and farms.
- The federal flood-control system on the lower Mississippi River and its tributaries includes more than 3,500 miles of levees, which guarantee that no town or farm will flood.
- The federal flood-control system on the lower Mississippi River and its tributaries includes more than 3,500 miles of levees, which protect towns and farmland.
How Sulfur Made Rubber Useful (student informative essay draft)
[1] Natural rubber begins as latex, a milky liquid that flows from cuts made in the bark of rubber trees, and people in the Americas were shaping balls and waterproof goods from it centuries before Europeans arrived. [2] In the early nineteenth century, manufacturers in the United States and Britain began selling rubber coats, shoes and other products, but the material had a serious practical flaw. [3] Untreated rubber turned soft and sticky in summer heat, and in winter cold it became hard and brittle. [4] As a result, rubber goods kept spoiling, and many of them were returned to the companies that had made them.
[5] Rubber behaves this way because it consists of extremely long, chain-shaped molecules that are not firmly attached to one another. [6] When the material is warm, the chains slide past each other easily, so the rubber softens and loses its shape; when it is cold, the chains stiffen and the rubber loses its stretch. [7] In 1839, the American inventor Charles Goodyear discovered that heating rubber with sulfur changed it permanently, and he received a United States patent for the process, patent number 3,633, on June 15, 1844.
[8] During heating, sulfur atoms form bridges, called cross-links, between neighboring chains. [9] The chains can no longer slide freely past one another. [10] Manufacturers only need like a tiny bit of sulfur for this, way less than you would think. [11] Once the chains are tied together, a stretched piece of rubber is pulled back toward its original shape instead of staying stretched or tearing apart.
[12] Vulcanized rubber, as the treated material came to be called, stays flexible across a much wider range of temperatures than untreated rubber. [13] Adding far more sulfur produces ebonite, a hard and rigid material that has been used for clarinet mouthpieces, electrical plugs and bowling balls. [14] Vulcanization made dependable hoses, shoe soles and conveyor belts possible, and it remains an essential step in the manufacture of tires today.
Jun wants one sentence to join [8] and [9] so the reader sees how they relate. Which sentence does that best?
- During heating, sulfur atoms form bridges, called cross-links, between neighboring chains; the chains can no longer slide freely past one another.
- During heating, sulfur atoms form bridges, called cross-links, between neighboring chains, although the chains can no longer slide freely past one another.
- The chains, which can no longer slide freely because sulfur atoms have formed cross-links between them during heating, remain inside the rubber.
- During heating, sulfur atoms form bridges, called cross-links, between neighboring chains, so the chains can no longer slide freely past one another.
Kira wants a comparison after [11] to help a reader picture the cross-linked chains. Which comparison fits the process best?
- The chains act much like drying glue, as the sulfur melts them together into one solid lump that can no longer stretch in any direction.
- It resembles a covalently bonded elastomeric network whose entropic restoring force returns the polymer to its unstrained conformation.
- The chains act like a net of cords knotted wherever two cords cross: the net stretches when pulled, and the knots draw it back when released.
- It is like a stick of butter, which turns hard and stiff in a cold refrigerator and then soft and easy to spread again on a warm kitchen counter.
Luz finds [10] too loose for an informative essay. Which revision of [10] meets the norms of the subject best?
- For every rubber product ever made, manufacturers have added exactly three parts of sulfur per hundred parts of rubber, with no variation.
- For most rubber goods, manufacturers add a small amount of sulfur compared with the much larger amount of rubber that goes into the mix.
- For most rubber goods, manufacturers add an astonishingly, unbelievably tiny pinch of sulfur that seems almost like magic to anyone who first hears of it.
- For most rubber goods, manufacturers add a few parts of sulfur, often between one and three, for every hundred parts of rubber.
How Water Wheels Powered Early Mills (student informative essay draft)
[1] For many centuries before steam engines were built, flowing water provided one of the most important sources of mechanical power for grinding grain, sawing wood and running other machines. [2] A water wheel captures that power by turning the energy of moving or falling water into the steady rotation of an axle. [3] Mill builders developed several varieties of wheel, and the variety they selected depended principally on the volume of water a stream delivered and the distance it could be made to fall.
[4] The simplest design is the undershot wheel, which sits in a stream so that the current pushes against paddles at the bottom of the wheel. [5] It needs no dam or raised channel, but because it relies on the push of the current alone, it turns much of the water's energy into wasted splashing and swirling. [6] An overshot wheel works on a different principle. [7] Water is carried in a wooden channel, called a flume, to the top of the wheel, where it pours into buckets on one side. [8] The buckets on that side fill with water. [9] The weight of the water pulls that side of the wheel down. [10] As each bucket reaches the bottom, it tips and empties, so the rising side stays light while the falling side stays heavy. [11] Because it uses the weight of falling water as well as its motion, an overshot wheel can turn most of the water's energy into useful work, far more than an undershot wheel can.
[12] Inside the mill, wooden gears changed the slow turning of the wheel's axle into the faster turning of a millstone or a saw. [13] Water wheels were super popular in England a long time ago, and there were a whole bunch of them. [14] The same basic idea survives in modern hydroelectric plants, where water falling through a turbine turns a generator instead of a millstone.
Milo wants one sentence to join [8] and [9] so the reader sees how they relate. Which sentence does that best?
- Although the buckets on that side fill with water, the weight of the water pulls that side of the wheel down.
- The wheel, whose side is pulled down by the weight of the water once the buckets on that side fill, stands beside the mill.
- As the buckets on that side fill with water, the weight of the water pulls that side of the wheel down.
- As the weight of the water pulls that side of the wheel down, the buckets on that side fill with water.
Why Old Faithful Erupts (student informative essay draft)
[1] Old Faithful, in Yellowstone National Park, is famous for erupting at fairly predictable intervals, and its regularity makes it a useful example for explaining how any geyser works. [2] Yellowstone holds more than half of the geysers in the world, because it has the three ingredients a geyser needs: a strong source of heat, a plentiful supply of water and a special kind of underground plumbing. [3] The heat comes from molten rock, called magma, that lies unusually close to the surface beneath the park.
[4] Rain and melted snow soak into the ground and trickle down through cracks until they reach rock heated by the magma below. [5] At sea level, water boils at 100 degrees Celsius, but water under greater pressure must become hotter before it can boil. [6] Deep in a geyser's plumbing, the weight of the water above presses down on the water below. [7] The water at the bottom can be heated well above its normal boiling point without turning to steam. [8] Water in this condition is described as superheated.
[9] The plumbing of a geyser includes a narrow passage, or constriction, near the surface, which keeps the water from rising freely and allows the pressure to build. [10] Eventually some of the water near the top boils and pushes a little water out of the vent, which lowers the pressure on the water beneath it. [11] With the pressure suddenly reduced, the superheated water flashes into steam all at once, and the expanding steam drives the column of water high into the air. [12] Old Faithful goes off about every hour and a half or so and shoots water really, really high.
[13] When the eruption ends, the plumbing slowly refills with water and the heating begins again, which is why a geyser erupts in cycles rather than in a steady stream. [14] Park rangers use the length of each eruption to predict the next one, because the interval before the next eruption depends on how long the previous eruption lasted.
Ren wants one sentence to join [6] and [7] so the reader sees how they relate. Which sentence does that best?
- Because the weight of the water above presses down on the deep water, the water at the bottom can be heated well above its normal boiling point without turning to steam.
- The weight of the water above presses down on the deep water, and the water at the bottom gets heated well above its normal boiling point.
- Although the weight of the water above presses down on the deep water, the water at the bottom can be heated well above its normal boiling point.
- Because the water at the bottom can be heated well above its normal boiling point, the weight of the water above presses down on it.
Tala wants a comparison after [10] to help a reader picture what happens next. Which comparison fits it best?
- It is like a pot of soup slowly warming on a stove for a long time before anything starts to bubble.
- It is like a balloon being blown up until it is stretched too far and suddenly bursts open.
- The effect resembles opening a shaken bottle of soda: once the pressure is released, the gas held in the liquid escapes at once and pushes the liquid out.
- It is like the earth itself clearing its throat, a grand performance staged by nature for an eager audience.
Zee finds [12] too loose for an informative essay. Which revision of [12] meets the norms of the subject best?
- Old Faithful erupts like clockwork and sends a breathtaking, sky-high blast of water soaring toward the clouds.
- Old Faithful erupts at a typical interval of about 90 minutes, sending water roughly 100 to 185 feet into the air.
- Old Faithful goes off after an hour and a half or so, and when it does, you will see it shoot way, way up into the sky.
- Old Faithful erupts fairly often during the day, sending water a long way up into the air.