The body that impacted Earth at the end of the Cretaceous period was a meteorite with a mass of more than a trillion tons and a diameter of at least 10 kilometers. Scientists first identified this impact in 1980 from the worldwide layer of sediment deposited from the dust cloud that enveloped the planet after the impact. This sediment layer is enriched in the rare metal iridium and other elements that are relatively abundant in a meteorite but very rare in the crust of Earth. Even diluted by the terrestrial material excavated from the crater, this component of meteorites is easily identified. By 1990 geologists had located the impact site itself in the Yucatán region of Mexico. The crater, now deeply buried in sediment, was originally about 200 kilometers in diameter.

According to paragraph 3, how did scientists determine that a large meteorite had impacted Earth?

A. They discovered a large crater in the Yucatán region of Mexico.
B. They found a unique layer of sediment worldwide.
C. They were alerted by archaeologists who had been excavating in the Yucatán region.
D. They located a meteorite with a mass of over a trillion tons.

Be careful when selecting your answer, because 3 of the 4 answer choices misstate information from the passage OR contradict information from the passage.
One answer we can definitely eliminate is C, because there is no mention in this paragraph of archeologists working in the Yucatan region.
Choice A looks like what is said here in the last two sentences, where it does say they found the crater in 1990. But they determined in 1980 that there was a meteorite impact, so it’s not choice A.
Choice D is incorrect because it says that “they located a meteorite,” which is not true because what they found was the crater, and other evidence of the meteorite impact, not the meteorite itself.
That leaves choice B, which is supported by the second and third sentences. The second sentence mentions “the worldwide layer of sediment” and the third sentence explains how it is unique. Therefore B is the correct answer.

Now let’s look at a Negative Factual Information question. Here is another paragraph about meteorite impacts from the same reading passage.
And here’s the question.

Negative Factual Information Questions

This impact released an enormous amount of energy, excavating a crater about twice as large as the lunar crater Tycho. The explosion lifted about 100 trillion tons of dust into the atmosphere, as can be determined by measuring the thickness of the sediment layer formed when this dust settled to the surface. Such a quantity of material would have blocked the sunlight completely from reaching the surface, plunging Earth into a period of cold and darkness that lasted at least several months. The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland. Presumably, those environmental disasters could have been responsible for the mass extinction, including the death of the dinosaurs.

According to paragraph 4, all of the following statements are true of the impact at the end of the Cretaceous period EXCEPT:

A. A large amount of dust blocked sunlight from Earth.
B. Earth became cold and dark for several months.
C. New elements were formed in Earth’s crust.
D. Large quantities of nitric acid were produced.

You know it’s a Negative Factual Information question because of the word EXCEPT in capital letters. So three of the choices are going to match information in the paragraph, and only one will not.
Let’s see how many correct choices we can find by scanning for key words that appear in the answers, like dust, sunlight, cold, dark, elements, crust, and nitric acid. We may also need to look for synonyms of these words.
So if we scan the paragraph for some text about dust and blocked sunlight that corresponds to choice A, we find this, and it’s a match.
Choice B is here, where it talks about the cold and darkness.
There is nothing in the paragraph that talks about new elements or the Earth’s crust, so choice C looks like it might be the answer.
For choice D, we found that information here, where it talks about nitric acid.
So choice C is our answer. 

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METRONITE IMPACTS

Here's an excerpt from the passage with the vocabulary word highlighted. 
Here's the sample question, which asks the meaning of the word "pose".

There is increasing evidence that the impacts of meteorites have had important effects on Earth, particularly in the field of biological evolution. Such impacts continue to pose a natural hazard to life on Earth.

The word "pose" is closest in meaning to

1. claim
2. model
3. assume
4. present

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Here's an example of a sentence simplification question from a passage about meteorite impacts and dinosaur extinction.
This type of question can be challenging, because all of the answer choices will contain words or phrases that are similar to ones in the given sentence.
For example, 3 of the answer choices talk about the explosion…
… 3 talk about fires
… and 3 mention the destruction of plant life

The explosion is also calculated to have produced vast quantities of nitric acid and melted rock that sprayed out over much of Earth, starting widespread fires that must have consumed most terrestrial forests and grassland.

1. Scientists believe that large amounts of nitric acid and melted rock were released by the explosion, causing fires that probably destroyed most of Earth's plant-life
2. Fires spread out over Earth, burning many forests and releasing nitric acid and other materials into the atmosphere.
3. Scientists have calculated the amount of nitric acid and melted rock that was released on Earth after the explosion.
4. Scientists believe that large fires in forests must have spread to grasslands and caused explosions that destroyed most of Earth's plants.

So, can you identify the correct answer? It's A, because all of the important information is aligned with the given sentence.
Both the given sentence and choice A talk about the large amounts of nitric acid and melted rock…
…that were the result of the explosion…
…and that started fires that destroyed plant life.

The other responses have content that contradicts the highlighted sentence or just isn't there.
Choice B looks like a good answer at first, because it talks about the fires spreading and burning forests… But choice B says that it was the fires that released the nitric acid, which is different from the highlighted sentence, which says that the nitric acid, along with the melted rock, caused the fires.

Choice C can be eliminated because it leaves out essential information about the fires and the destruction of forests and plant life.

Finally, choice D is incorrect because again, the cause and effect are reversed. This one says that the fires caused the explosions when it was really the other way around.

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Look at the four squares [■] that indicate where the following sentence can be added to the passage.

Some companies in the power industry are aware of this wider possibility and are planning sizable wind-farm projects in states other than California.

Where would the sentence best fit?

Since 1980, the use of wind to produce electricity has been growing rapidly. Some companies in the power industry are aware of this wider possibility and are planning sizable wind-farm projects in states other than California. In 1994 there were nearly 20,000 wind turbines worldwide, most grouped in clusters called wind farms that collectively produced 3,000 megawatts of electricity. ■ Most were in Denmark (which got 3 percent of its electricity from wind turbines) and California (where 17,000 machines produced 1 percent of the state's electricity, enough to meet the residential needs of a city as large as San Fransico). ■ In principle, all the power needs of the United States could be provided by exploiting the wind potential of just three states – North Dakota, South Dakota, and Texas. ■
Large wind farms can be built in six months to a year and then easily expanded as needed. With a moderate to fairly high net energy yield, these systems emit no heat-trapping carbon dioxide or other air pollutants and need no water for cooling; manufacturing them produces little water pollution. The land under wind turbines can be used for grazing cattle and other purposes, and leasing land for wind turbines can provide extra income for farmers and rachers.

Since 1980, the use of wind to produce electricity has been growing rapidly. ■ In 1994 there were nearly 20,000 wind turbines worldwide, most grouped in clusters called wind farms that collectively produced 3,000 megawatts of electricity. Some companies in the power industry are aware of this wider possibility and are planning sizable wind-farm projects in states other than California Most were in Denmark (which got 3 percent of its electricity from wind turbines) and California (where 17,000 machines produced 1 percent of the state's electricity, enough to meet the residential needs of a city as large as San Fransico). ■ In principle, all the power needs of the United States could be provided by exploiting the wind potential of just three states – North Dakota, South Dakota, and Texas. ■
Large wind farms can be built in six months to a year and then easily expanded as needed. With a moderate to fairly high net energy yield, these systems emit no heat-trapping carbon dioxide or other air pollutants and need no water for cooling; manufacturing them produces little water pollution. The land under wind turbines can be used for grazing cattle and other purposes, and leasing land for wind turbines can provide extra income for farmers and rachers.

Here's a sample Insert Text question, and the corresponding paragraph.

On-screen: Look at the four squares [■] that indicate where the following sentence can be added to the passage.

This is the criterion emphasized by Darwin's theory of evolution by natural selection.

Where would the sentence best fit?

Impacts by meteorites represent one mechanism that could cause global catastrophes and seriously influence the evolution of life all over the planet. ■ According to some estimates, the majority of all extinctions of species may be due to such impacts. ■ Such a perspective fundamentally changes our view of biological evolution. ■ The standard criterion for survival of a species is its success in competing with other species and adapting to slowly changing environments. This is the criterion emphasized by Darwin's theory of evolution by natural selection. Yet an equally important criterion is the ability of a species to survive random global ecological catastrophes due to impacts.

Note that the sentence says "This is the criterion…" And it's important to look for pronouns. The pronoun here is "this," so there is probably something about a criterion in the previous sentence.
If we insert the sentence at square number 4, the previous sentence talks about "the standard criterion," and the following sentence says "Yet an equally important criterion". So that's a likely choice. And when you read those sentences together, the sentences do flow logically. So this is the correct answer.

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Let's look at a sample prose summary question.  Here's the passage about meteorites and dinosaur extinction.

Text, There is increasing evidence that the impacts of meteorites have had important effects on Earth, text continues.

And here's the question.

Asks to select 3 of 6 choices.

Now let's look at each of the answer choices to see which three are correct.

• Answer number one isn't supported by any of the information in the passage. So we know that this one is not correct.
• Answer number two is a factually correct statement, but identifying the specific date when something happened, generally, doesn't qualify as one of the most important ideas. So this one is probably not correct. But let's look at the others to make sure.
• For answer number three, the reference to the crater Tycho is used to give a sense of the size of the crater that struck the Yucatan. However, the topic of meteorite activity on the moon is not a focus of this passage.
• Answer number four combines several facts that together provide a summary of an important idea from the passage. This is supported by information given in paragraphs two and three.
• Answer number five is about the effects of meteorite impacts, which is an important idea of the passage. We can see this in paragraph four, where it talks about the mass destruction from the cold, darkness, and fires and in paragraph five where it talks about the catastrophic results. The other relevant passage, implicating impacts in extinctions, is also highlighted.
• Answer number six is another important idea that is stated in a similar sentence in paragraph five. What is a catastrophe for one group of living things however may create opportunities for another group. So for this question, answers four, five, and six are the correct three choices.

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