Exercises for Determining Main Ideas

Exercises for determining main ideas

(The passages from Milanda Broukal’s In-a-Flash Reading for the TOEFL Test by Thomson)

Read each passage below and choose the main idea from statements (A)-(D). (Which statement is too general? Which is too specific? Which is incorrect?)

1.

Birds have two basic types of sounds: songs and calls. Songs are usually more complex than calls and are utilized primarily by adult males during the breeding season to establish territories or attract mates. Calls are normally simple notes, single or repeated, vocalized by males and females in all seasons to express alarm or maintain contact with mates, offspring, or other birds of the same species. All songs and most calls are distinctive, and with concentrated study and practice, bird-watchers can learn to identify many birds by their sounds and to call them as well.

(A) Bird calls and songs are distinctive, meaningful, and identifiable.

(B) Bird songs are complicated and used mainly by males to attract mates.

(C) Birds have their own language by which they maintain contact.

(D) Bird-watchers can identify many bird calls and their meanings and learn to mimic them as well.

noun / verb / adjective, adverb / others
mate
offspring / breed
vocalize / distinctive

1. having a quality or characteristic that makes something different and easily noticed; characteristic ( )

2. either of a pair of birds or animals ( )

3. (of animals) to have sex and produce young ( )

4. a child of a particular person or couple ( )

5. to say or sing sounds or words ( )

Many animals breed only at certain times of the year.

A male bird sings to attract a mate.

Your baby will begin to vocalize long before she can talk.

Most parents have problems with their teenage offspring.

The male bird has distinctive white markings on its head.

2.

Strictly speaking, cartography is the drawing or compiling of maps. The explorers and surveyors go out and make the measurements and gather the information from which the cartographers draw their maps. Sometimes the fieldwork and the creation of the map are done by the same person. But when the scope is broad and the sources of information many, maps are more often a compilation of that information. They represent the accumulated work of many people, brought together under the supervision of one person, the compiler. The value of the map depends, of course, on the expertise of the compiler, who must sift through available information, select the most accurate data, and come up with a thoughtful and accurate synthesis of the geographic knowledge of the region.

(A) The definition of cartography is the drawing or compiling of maps.

(B) Maps are the product of a group effort brought together usually by one person.

(C) Not all of the information initially compiled for maps is accurate.

(D) The compiler’s task is more important than that of the explorers and surveyors.

noun / verb / adjective, adverb / others
cartography
compilation
expertise
supervision
surveyor
synthesis / accumulate
come up with
compile
sift through

1. someone whose job is to examine the condition of a building, or to measure and record the details of an area of land ( )

2. to make a book, list, or record, using different pieces of information or music ( )

3. a collection of items, especially pieces of information or songs, taken from different places and put together ( )

4. something that has been made by combining different things, or the process of combining things ( )

5. to gradually get more and more money, possessions, or knowledge over a period of time ( )

6. special skills or knowledge in a particular subject, that you learn by experience or training ( )

7. to think of an idea or answer ( )

8. when you supervise someone or something ( )

9. to examine information or documents carefully in order to find something out or decide what is important and what is not ( )

10. the activity of making maps ( )

Digital cartography promises a more efficient and flexible way of doing this kind of work.

Her latest CD is a compilation of all her best singles.

His expertise will be invaluable to understanding technological challenges the BBC is facing.

The drug should only be used under medical supervision.

a synthesis of scientific knowledge and religious faith

It is unjust that a privileged few should continue to accumulate wealth.

Is that the best excuse you can come up with?

The report was compiled from a survey of 5,000 households.

Police are sifting through the evidence in the hope of finding more clues.

3.

Speculation about the earth’s crust has a special edge of urgency in California, which sits on the San Andreas fault, the world’s most famous and respected fracture zone. Not surprisingly, it was a scientist at the California Institute of Technology, Charles F. Richter, who invented the Richter scale used to measure earthquakes. Seismic activity in California is being constantly monitored and mapped. Seismometers register many thousands of small earthquakes every year, and computers instantly calculate the location, depth, and magnitude of an earthquake. Laser distance-ranging networks can detect changes of length, indicating change in crustal stress, accurate to about half an inch in 20 miles. Satellite measurements of crustal blocks are improving, and California seismologists believe they may in time be precise enough to allow earthquake prediction.

(A) The Richter scale was invented in California.

(B) Computers provide a variety of information about earthquakes.

(C) A great deal of attention is paid to earthquake activity in California.

(D) Earthquake prediction will be possible in the future.

noun / verb / adjective, adverb / others
crust
edge
fault
fracture
seismologist
seismometer
speculation / register / seismic

1. the hard outer layer of the Earth ( )

2. an instrument that measures and records the movement of the earth during an earthquake ( )

3. a large crack in the rocks that form the Earth’s surface ( )

4. when you guess about the possible causes or effects of something without knowing all the facts, or the guesses that you make ( )

5. a scientist who studies earthquakes ( )

6. keenness or intensity of desire or enjoyment ( )

7. (of a measuring instrument) to show or record the amount of something ( )

8. [technical] relating to or caused by earthquakes ( )

9. a crack or broken part in a bone or other hard substance ( )

The continents sit on shifting plates that form the outer crust of the Earth

I lost my competitive edge.

the San Andreas fault in Northern California

Hip fractures, which especially plague older women, are the most serious fall injury for seniors.

There is speculation that the president is ill.

The Geiger counter registered a dangerous level of radioactivity.

The latest seismic activity was also felt in northern Japan.

4.

Innovations in transportation in the 1800s permitted space to be traversed more rapidly and were crucial to the industrial expansion of the North. The great spaces that separated producers from consumers made speed essential, especially in the movement of perishable freight. The development of the steam-powered locomotive in the 1830s and the rapid extension of the railways in the 1840s and 1850s provided the answer to the need for faster transport and dramatically altered patterns of economic development throughout the United States. In 1830 there were 32 miles of rails in the country, in 1840 there were 2,818 miles, and by 1850 there were more than 9,000 miles. The rapid extension of rail mileage enabled the railroads to significantly reduce their costs for shipping freight and carrying passengers, thus enabling them to price their services more cheaply and competitively. The extension of trunk lines, into which short or local lines fed, further tightened the east-west flow of commerce and bound the Northeast and the old Northwest together with bands of steel.

(A) Railroad made the transportation of perishable freight possible.

(B) Between 1830 and 1850 over 8,000 miles of railroad track were laid.

(C) Railroads provided an important link between the Northwest and the Northeast.

(D) Railroads had a profound effect on the economic development of the United States in the nineteenth century.

noun / verb / adjective, adverb / others
freight
innovation
locomotive
mileage
trunk line / feed into
ship
traverse / crucial to
perishable

1. a new idea, method, or invention ( )

2. [formal] to move across, over, or through something, especially an area of land or water ( )

3. the number of miles that is covered by a country’s railways ( )

4. extremely important, because everything else depends on it ( )

5. a railway engine ( )

6. to become channeled or directed ( )

7. a transportation system such as a railroad or highway used for traveling long distances ( )

8. (of food) likely to decay quickly ( )

9. goods that are carried by ship, train, or aircraft, and the system of moving these goods ( )

10. to send goods somewhere by ship, plane, or truck ( )

We’ll send your personal belongings by air freight and your furniture by sea freight.

Innovations in information technology have completely transformed the way students work.

The decision making process can be likened to one of those great lumbering steam locomotives seen in Western films.

The plans are announced to treble the country’s railway mileage.

The river feeds into the Atlantic ocean.

About half of the whisky produced in Scotland is shipped to Japan and the US.

An estimated 250,000 cars traverse the bridge daily.

Winning this contract is crucial to the success of the company.

perishable goods such as butter, milk, fruit, and fish

5.

Because different tree species adapted to different climates and soil types have evolved over millennia, many kinds of forests occupy the earth today. The primitive forests of several hundred million years ago consisted of fewer kinds of trees. In fact, the earliest “trees,” which grew nearly 500 million years ago, were like giant club mosses. They lacked true roots and consisted of a tangle of specialized branches that clambered over rocky ground. Fifty million years later came the dense forests of tree ferns that prevailed in tropical climates of that era. The forerunners of modern conifers were on the scene 300 million years ago, when plant life abundantly colonized marshy land, building the tremendous coal and oil reserves so important today. By the time the dinosaurs roamed the earth some 180 million years ago, during the Cretaceous period, seed-bearing trees had evolved that shed their leaves in winter; from these have sprung the angiosperms and our present deciduous forests.

(A) Conifers are the oldest trees in today’s forests.

(B) Climate affected the development of trees over millennia.

(C) The predecessors of today’s forests were giant club mosses and tree ferns.

(D) The variety of trees in today’s forest are a result of millions of years of evolution.

noun / verb / adjective, adverb / others
conifer
fern
forerunner
millennium
reserve
tangle / adapt
clamber
colonize
evolve
prevail
roam
shed / deciduous
marshy

1. someone or something that existed before something similar that developed or came later ( )

2. a twisted mass of something such as hair or thread ( )

3. a period of 1000 years ( )

4. to gradually change your behavior and attitudes in order to be successful in a new situation ( )

5. a tree such as a pine or fir that has leaves like needles and produces brown cones that contain seeds. Most types of this keep their leaves in winter ( )

6. to climb or move slowly somewhere, using your hands and feet because it is difficult or steep ( )

7. a supply of something kept to be used if it is needed ( )

8. if animals or plants ( ) an area, large numbers of them start to live there

9. a type of plant with green leaves shaped like large feathers, but no flowers ( )

10. [formal] to exist or be very common at a particular time or in a particular place ( )

11. if plants ( ) their leaves, they lose them naturally

12. of or relating to a marsh(=an area of low flat ground that is always wet and soft) ( )

13. to walk or travel, usually for a long time, with no clear purpose or direction ( )

14. ( ) trees lose their leaves in winter

15. if animals or plants ( ), they change gradually over a long period of time

If the conifers win out, then they shade the ground permanently and only mosses can remain.

In general, ferns like organically enriched, moist but well-draining soil on the acid side.

The ice safe kept in the cellar was a forerunner of today’s refrigerator.

The tribes have inhabited this land for millennia.

As oil reserves are depleted, its price will continue to rise.

She followed him, pushing through the dense tangle of bushes and branches.

These flowers are well adapted to harsh winters.

They clambered over the slippery rocks.

a dead tree that has been colonized by ants

Fish evolved from prehistoric sea creatures.

Those beliefs still prevail among certain social groups.

Chickens and geese roam freely in the back yard.

The trees were starting to shed their leaves.

Once the Cotswolds had probably consisted of deciduous forest, with beech the dominant tree.