Free TOEFL iBT mock — new format, timed diagnostic 🇺🇸

8 original practice questions written by Myndaq in the TOEFL iBT style. They are not taken from this mock paper or from official past papers. Try each one, then open the answer.

1. Question 1ReadingOne correct answer

   Lichens are not single organisms but partnerships, usually between a fungus and an alga that lives among its threads. The fungus supplies shelter and mineral salts; the alga supplies sugars made by photosynthesis. Because a lichen has no roots and no waxy outer skin, it takes in water and dissolved minerals over its entire surface, straight from rain, mist and settling dust. Anything carried in that moisture enters the tissue along with it.

   That habit makes lichens sensitive recorders of air quality. Botanists working in nineteenth-century manufacturing towns noticed that shrubby, branching species disappeared first near foundries and railway yards, while flat crust-forming species clung on much longer. The cause was sulfur dioxide from coal smoke. By the 1970s surveyors had turned the pattern into ranked scales, reading the mixture of species on a wall or a tree trunk as a rough measure of the surrounding air.

   Newer pollutants complicate the picture. Nitrogen compounds drifting from fertilized fields and from traffic act as a fertilizer for certain lichens, which spread vigorously while more sensitive neighbors retreat. A simple count of species may therefore stay steady even as the community is transformed. Lichens also grow slowly, so what they show is an accumulation built up over years rather than the conditions of a single week, which makes them a useful complement to instruments that sample the air for a few hours at a time.

   According to paragraph 1, why do substances dissolved in rain end up inside a lichen?

   1. A. The fungal threads actively pump minerals out of the air and pass them to the alga.
   2. B. The lichen has no roots and no waxy covering, so it absorbs moisture across its whole surface.
   3. C. Photosynthesis in the alga requires a steady upward flow of dissolved minerals.
   4. D. Dust settles on the lichen and is later washed down into the soil beneath it.
   Show answer and explanation

   Answer: B

   Paragraph 1 states that because a lichen lacks roots and a waxy outer skin, it takes in water and dissolved minerals over its entire surface, and that anything carried in the moisture enters the tissue with it. That is choice B.

   Choice A invents an active pumping mechanism the passage never describes; the fungus is said only to supply shelter and mineral salts. Choice C reverses the relationship, since the passage links absorption to the absence of a protective surface, not to the needs of photosynthesis. Choice D describes water leaving the lichen for the soil, the opposite of the uptake being explained.

2. Question 2ReadingOne correct answer

   Lichens are not single organisms but partnerships, usually between a fungus and an alga that lives among its threads. The fungus supplies shelter and mineral salts; the alga supplies sugars made by photosynthesis. Because a lichen has no roots and no waxy outer skin, it takes in water and dissolved minerals over its entire surface, straight from rain, mist and settling dust. Anything carried in that moisture enters the tissue along with it.

   That habit makes lichens sensitive recorders of air quality. Botanists working in nineteenth-century manufacturing towns noticed that shrubby, branching species disappeared first near foundries and railway yards, while flat crust-forming species clung on much longer. The cause was sulfur dioxide from coal smoke. By the 1970s surveyors had turned the pattern into ranked scales, reading the mixture of species on a wall or a tree trunk as a rough measure of the surrounding air.

   Newer pollutants complicate the picture. Nitrogen compounds drifting from fertilized fields and from traffic act as a fertilizer for certain lichens, which spread vigorously while more sensitive neighbors retreat. A simple count of species may therefore stay steady even as the community is transformed. Lichens also grow slowly, so what they show is an accumulation built up over years rather than the conditions of a single week, which makes them a useful complement to instruments that sample the air for a few hours at a time.

   The word 'retreat' in paragraph 3 is closest in meaning to

   1. A. become less abundant
   2. B. change color
   3. C. grow more thickly
   4. D. move to shaded surfaces
   Show answer and explanation

   Answer: A

   In the sentence, nitrogen-loving lichens 'spread vigorously while more sensitive neighbors retreat'. The contrast with spreading shows that retreat means declining in extent or numbers, so 'become less abundant' fits.

   'Grow more thickly' is the opposite of the contrast the sentence sets up. 'Change color' and 'move to shaded surfaces' describe changes the passage never mentions, and lichens fixed to a wall or trunk do not relocate.

3. Question 3ReadingOne correct answer

   Lichens are not single organisms but partnerships, usually between a fungus and an alga that lives among its threads. The fungus supplies shelter and mineral salts; the alga supplies sugars made by photosynthesis. Because a lichen has no roots and no waxy outer skin, it takes in water and dissolved minerals over its entire surface, straight from rain, mist and settling dust. Anything carried in that moisture enters the tissue along with it.

   That habit makes lichens sensitive recorders of air quality. Botanists working in nineteenth-century manufacturing towns noticed that shrubby, branching species disappeared first near foundries and railway yards, while flat crust-forming species clung on much longer. The cause was sulfur dioxide from coal smoke. By the 1970s surveyors had turned the pattern into ranked scales, reading the mixture of species on a wall or a tree trunk as a rough measure of the surrounding air.

   Newer pollutants complicate the picture. Nitrogen compounds drifting from fertilized fields and from traffic act as a fertilizer for certain lichens, which spread vigorously while more sensitive neighbors retreat. A simple count of species may therefore stay steady even as the community is transformed. Lichens also grow slowly, so what they show is an accumulation built up over years rather than the conditions of a single week, which makes them a useful complement to instruments that sample the air for a few hours at a time.

   Why does the author mention instruments that sample the air for a few hours at a time?

   1. A. To argue that such instruments give unreliable readings near foundries
   2. B. To explain how surveyors calibrated their ranked scales in the 1970s
   3. C. To emphasize, by contrast, that lichens register exposure built up over long periods
   4. D. To show that lichen surveys cost less than continuous monitoring equipment
   Show answer and explanation

   Answer: C

   The reference comes immediately after the statement that lichens grow slowly and show an accumulation built up over years rather than the conditions of a single week. The short sampling period of the instruments is raised as the contrast that makes the slow record valuable, so C states the purpose.

   A is wrong because the passage never questions the accuracy of the instruments; it calls lichens a complement to them. B attaches the mention to the ranked scales of the previous paragraph, which are read from species mixtures, not from instruments. D introduces cost, a subject the passage does not raise at all.

4. Question 4ReadingOne correct answer

   Lichens are not single organisms but partnerships, usually between a fungus and an alga that lives among its threads. The fungus supplies shelter and mineral salts; the alga supplies sugars made by photosynthesis. Because a lichen has no roots and no waxy outer skin, it takes in water and dissolved minerals over its entire surface, straight from rain, mist and settling dust. Anything carried in that moisture enters the tissue along with it.

   That habit makes lichens sensitive recorders of air quality. Botanists working in nineteenth-century manufacturing towns noticed that shrubby, branching species disappeared first near foundries and railway yards, while flat crust-forming species clung on much longer. The cause was sulfur dioxide from coal smoke. By the 1970s surveyors had turned the pattern into ranked scales, reading the mixture of species on a wall or a tree trunk as a rough measure of the surrounding air.

   Newer pollutants complicate the picture. Nitrogen compounds drifting from fertilized fields and from traffic act as a fertilizer for certain lichens, which spread vigorously while more sensitive neighbors retreat. A simple count of species may therefore stay steady even as the community is transformed. Lichens also grow slowly, so what they show is an accumulation built up over years rather than the conditions of a single week, which makes them a useful complement to instruments that sample the air for a few hours at a time.

   Paragraph 3 suggests which of the following about a lichen survey carried out in farmland receiving heavy nitrogen deposition?

   1. A. It would record a sharp fall in the total number of species present.
   2. B. It could overlook the pollution if it noted only how many species were found.
   3. C. It would show that sulfur dioxide remains the main threat to sensitive species.
   4. D. It would find that lichens no longer grow on walls or tree trunks in the area.
   Show answer and explanation

   Answer: B

   The paragraph says that nitrogen favors certain lichens, which spread while sensitive species retreat, so a simple count of species may stay steady even though the community has been transformed. A survey limited to counting species could therefore miss the change, which is B.

   A contradicts the stated point that the count may stay steady. C is wrong because sulfur dioxide belongs to the historical case in paragraph 2 and is not named as the current threat. D overstates the passage, which describes a shift in which species are present, not the disappearance of lichens.

5. Question 5ReadingOne correct answer

   When beavers settle on a small stream they build low dams of branches and mud across it. The structures are never watertight; water seeps through the weave and spills over the crest, so the current is slowed rather than stopped. Behind each dam a shallow pond forms, and silt the water was carrying drops out and settles on the bed.

   Hydrologists have measured what this does to floods. On headwater streams draining a few square kilometers, a chain of ponds can hold back enough of a storm's runoff to flatten and delay the peak that arrives downstream. The gain is real but modest, and it shrinks as catchments grow larger, because the volume held behind the dams becomes an ever smaller share of the water a big river carries. It shrinks too when the ground is already saturated and the ponds are brim full before the rain begins.

   The animals are less welcome where their ponds reach roads and fields. A dam built against a culvert can flood a lane, and ponded water can drown pasture and young trees. Where the conflict is manageable, engineers install a pipe that runs through the dam and draws water from well upstream of it, so the pond sits at a level people can live with. Beavers locate leaks by the sound and feel of escaping water at the dam itself, and they generally leave such a pipe alone.

   According to paragraph 2, all of the following reduce the flood-control benefit of beaver dams EXCEPT

   1. A. an increase in the size of the catchment drained by the stream
   2. B. ground that is already saturated when the rain starts
   3. C. ponds that are filled to the brim before the storm arrives
   4. D. water that seeps through the woven branches of a dam
   Show answer and explanation

   Answer: D

   Paragraph 2 names three limits: the benefit shrinks as catchments grow larger, when the ground is already saturated, and when the ponds are brim full before the rain. Those match A, B and C.

   Seepage through the dam is mentioned in paragraph 1, and it is presented as the reason the current is slowed rather than stopped, not as something that reduces flood control. D is therefore the choice that is not given as a limit.

6. Question 6ReadingOne correct answer

   When beavers settle on a small stream they build low dams of branches and mud across it. The structures are never watertight; water seeps through the weave and spills over the crest, so the current is slowed rather than stopped. Behind each dam a shallow pond forms, and silt the water was carrying drops out and settles on the bed.

   Hydrologists have measured what this does to floods. On headwater streams draining a few square kilometers, a chain of ponds can hold back enough of a storm's runoff to flatten and delay the peak that arrives downstream. The gain is real but modest, and it shrinks as catchments grow larger, because the volume held behind the dams becomes an ever smaller share of the water a big river carries. It shrinks too when the ground is already saturated and the ponds are brim full before the rain begins.

   The animals are less welcome where their ponds reach roads and fields. A dam built against a culvert can flood a lane, and ponded water can drown pasture and young trees. Where the conflict is manageable, engineers install a pipe that runs through the dam and draws water from well upstream of it, so the pond sits at a level people can live with. Beavers locate leaks by the sound and feel of escaping water at the dam itself, and they generally leave such a pipe alone.

   According to paragraph 2, why does the effect of beaver ponds on flood peaks weaken in large catchments?

   1. A. Larger rivers wash the dams away before a flood peak can form.
   2. B. Beavers build fewer dams on the wide channels of large rivers.
   3. C. The water stored behind the dams is small compared with the river's total flow.
   4. D. Silt fills the ponds more quickly where the catchment is large.
   Show answer and explanation

   Answer: C

   The paragraph states the reason directly: as catchments grow larger, the volume held behind the dams becomes an ever smaller share of the water a big river carries. That is choice C, a question of proportion.

   A and B describe events the passage never reports, and nothing is said about dams failing or about how many dams beavers build on large rivers. D borrows the silt from paragraph 1, where settling silt is simply a consequence of the still water, not a cause of weaker flood control.

7. Question 7ReadingOne correct answer

   When beavers settle on a small stream they build low dams of branches and mud across it. The structures are never watertight; water seeps through the weave and spills over the crest, so the current is slowed rather than stopped. Behind each dam a shallow pond forms, and silt the water was carrying drops out and settles on the bed.

   Hydrologists have measured what this does to floods. On headwater streams draining a few square kilometers, a chain of ponds can hold back enough of a storm's runoff to flatten and delay the peak that arrives downstream. The gain is real but modest, and it shrinks as catchments grow larger, because the volume held behind the dams becomes an ever smaller share of the water a big river carries. It shrinks too when the ground is already saturated and the ponds are brim full before the rain begins.

   The animals are less welcome where their ponds reach roads and fields. A dam built against a culvert can flood a lane, and ponded water can drown pasture and young trees. Where the conflict is manageable, engineers install a pipe that runs through the dam and draws water from well upstream of it, so the pond sits at a level people can live with. Beavers locate leaks by the sound and feel of escaping water at the dam itself, and they generally leave such a pipe alone.

   The word 'modest' in paragraph 2 is closest in meaning to

   1. A. limited in size
   2. B. short-lived
   3. C. hard to measure
   4. D. widely accepted
   Show answer and explanation

   Answer: A

   The sentence says the gain is real but modest, and the rest of the paragraph explains the conditions under which it shrinks further. The contrast with 'real' marks modest as meaning small in degree, so 'limited in size' is closest.

   'Short-lived' concerns duration rather than magnitude, and the delay of the flood peak is not said to be brief. 'Hard to measure' contradicts the opening of the paragraph, where hydrologists have measured the effect, and 'widely accepted' describes opinion rather than the size of the benefit.

8. Question 8ReadingOne correct answer

   When beavers settle on a small stream they build low dams of branches and mud across it. The structures are never watertight; water seeps through the weave and spills over the crest, so the current is slowed rather than stopped. Behind each dam a shallow pond forms, and silt the water was carrying drops out and settles on the bed.

   Hydrologists have measured what this does to floods. On headwater streams draining a few square kilometers, a chain of ponds can hold back enough of a storm's runoff to flatten and delay the peak that arrives downstream. The gain is real but modest, and it shrinks as catchments grow larger, because the volume held behind the dams becomes an ever smaller share of the water a big river carries. It shrinks too when the ground is already saturated and the ponds are brim full before the rain begins.

   The animals are less welcome where their ponds reach roads and fields. A dam built against a culvert can flood a lane, and ponded water can drown pasture and young trees. Where the conflict is manageable, engineers install a pipe that runs through the dam and draws water from well upstream of it, so the pond sits at a level people can live with. Beavers locate leaks by the sound and feel of escaping water at the dam itself, and they generally leave such a pipe alone.

   Paragraph 3 implies that the pipe succeeds mainly because

   1. A. its intake lies away from the dam, so the beavers meet no cue that prompts them to repair anything
   2. B. its opening is too narrow for a beaver to plug with branches and mud
   3. C. beavers abandon a pond as soon as its water level begins to fall
   4. D. it strengthens the dam and so makes the beavers less anxious about leaks
   Show answer and explanation

   Answer: A

   The paragraph pairs two facts: the pipe draws water from well upstream of the dam, and beavers find leaks by the sound and feel of escaping water at the dam itself. Taken together, they imply that the draining goes on out of range of the cues beavers respond to, which is A.

   B adds a detail about the pipe's width that the passage never supplies. C contradicts the purpose of the device, which is to keep a pond at a workable level rather than to drive the animals away. D misreads the pipe as reinforcement and attributes an emotional state to the beavers instead of the sensory cue described.