The Cretaceous-Tertiary extinction event, or the K-T event, is the name given to the die-off of the dinosaurs and other species that took place some 65.5 million years ago. For many years, paleontologists believed this event was caused by climate and geological changes that interrupted the dinosaurs’ food supply. However, in the 1980s, father-and-son scientists Luis (1911-88) and Walter Alvarez (1940-) discovered in the geological record a distinct layer of iridium–an element found in abundance only in space–that corresponds to the precise time the dinosaurs died. This suggests that a comet, asteroid or meteor impact event may have caused the extinction of the dinosaurs. In the 1990s, scientists located the massive Chicxulub Crater at the tip of Mexico’s Yucatán Peninsula, which dates to the period in question.
Dinosaurs roamed the earth for 160 million years until their sudden demise some 65.5 million years ago, in an event now known as the Cretaceous-Tertiary, or K-T, extinction event. (“K” is the abbreviation for Cretaceous, which is associated with the German word “Kreidezeit.”) Besides dinosaurs, many other species of mammals, amphibians and plants died out at the same time. Over the years, paleontologists have proposed several theories for this extensive die-off. One early theory was that small mammals ate dinosaur eggs, thereby reducing the dinosaur population until it became unsustainable. Another theory was that dinosaurs’ bodies became too big to be operated by their small brains. Some scientists believed a great plague decimated the dinosaur population and then spread to the animals that feasted on their carcasses. Starvation was another possibility: Large dinosaurs required vast amounts of food and could have stripped bare all the vegetation in their habitat. But many of these theories are easily dismissed. If dinosaurs’ brains were too small to be adaptive, they would not have flourished for 160 million years. Also, plants do not have brains nor do they suffer from the same diseases as animals, so their simultaneous extinction makes these theories less plausible.
Answer: Option(a) is correct option
Explanation:
Normative statements are the statements that include value that is used for describing desirability and undesirability of situation.It is based on further requirements, need and perspective.
According to the question, statement that provide description about world should be is a normative statement as it describes the possible requirements for world .
Other options are incorrect because descriptive statement is based on objective and facts. Economist hired by government or in scientific field is not described through world description. Thus, the correct option is option(a).
How many syllables in alteration? 4 syllables
Divide alteration into syllables: al-ter-a-tion
Primary syllable stress: al-ter-a-tion
Secondary syllable stress: al-ter-a-tion
How to pronounce alteration: awl-ter-ey-shun
An element <u>period </u>is its row in the periodic table.
The typical individual's innate abilities that is independent of acquired knowledge and experience constitute is known as Fluid intelligence.
<h3>What is
Fluid intelligence?</h3>
This refers to individual's ability to think and reason abstractly and solve problems.
Hence, it involves individual's innate abilities that is independent of acquired knowledge and experience constitute.
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