“Scientists continued to gather information about black holes, but they could not confirm their existence until Cygnus X-1 was discovered in 1964. Astronomers were using radio telescopes to observe the constellation Cygnus (the Swan) when they detected high-energy x-rays and gamma rays. This radiation was being emitted as a black hole consumed gas from a blue supergiant star that was closely orbiting. As the gas spiraled down into the black hole, it formed a super hot accretion disk around it that was releasing bursts of electromagnetic radiation. Since then, many more black holes have been detected in various ways. Since a black hole’s gravity will pull on nearby objects, scientists can look for stars that make erratic movements when they pass by a black hole. Stars can also orbit black holes, so when a star appears to be orbiting nothing, it may be orbiting one.”

According to paragraph, which of the following is true about Cygnus X 1?

• It is a blue supergiant star that orbits a black hole.
• It is located in a galaxy that is shaped like a swan.
• It was the first confirmed black hole to be detected.
• It emits high-energy x-rays and gamma-rays.

It was the first confirmed black hole to be detected.

If you read carefully, the same statement is prenent in the text.

Darwin's theory posits that 'natural selection' acts as the engine behind evolution, resembling a form of 'selective breeding' occurring in nature. This theory forms a solid basis for understanding the gradual changes organisms undergo over time. Nonetheless, being a theory, it remains elusive and challenging to definitively prove. One of the primary challenges to Darwin's theory revolves around the concept of "irreducibly complex systems." An irreducibly complex system refers to a system where numerous distinct parts must function together in unison, as the absence of even a single component would lead to the collapse of the entire system. With advancements in modern technology, scientists can now identify such "irreducibly complex systems," even at the microscopic level. If these complex systems indeed rely on intricate interdependencies, they pose a significant challenge to Darwin's hypothesis concerning the process of evolution. As Darwin himself candidly admitted, "To suppose that the eye, with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for correcting spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree."

All of the following are mentioned in paragraph as a viewpoint to state the natural selection is difficult to prove EXCEPT.

• The notion that natural selection could account for the intricate complexity of the human eye appears highly implausible.
• The existence of irreducibly complex systems contradicts the mechanisms of evolution.
• Modern microbiology provides evidence for the existence of irreducibly complex systems.
• The presence of selective breeding poses a significant challenge to the theory of natural selection.

The presence of selective breeding poses a significant challenge to the theory of natural selection.

Selective breeding is not a major hole but the presence of it is complex.

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.

Which of the following can be inferred from the paragraph about the location of the meteorite impact in Mexico?

• The location of the impact site in Mexico was kept secret by geologists from 1980 to 1990.
• It was a well-known fact that the impact had occurred in the Yucatán region.
• Geologists knew that there had been an impact before they knew where it had occurred.
• The Yucatán region was chosen by geologists as the most probable impact site because of its climate.

Geologists knew that there had been an impact before they knew where it had occurred.

The collision happened in 1980. Deologists did not locate the area until 1990.

“All environmental factors cause the body physical stress, but they also cause mental stress, which can be equally influential if not more so. Scientific studies with mice have shown that mental stress can cause hormone imbalances that result in epigenetic changes. In one experiment, mice were restrained, which raised their stress levels and triggered higher levels of N6-methyladenine (6mA) in their brains, which resulted in epigenetic changes. In another experiment, mice were given water with corticosterone, the mouse equivalent of the human stress hormone cortisol, for four weeks. This put them into a heightened state of stress and caused them to have fewer methyl groups on gene Fkbp5, which increased protein production. The different epigenetic markers lasted for weeks after they stopped receiving corticosterone, which suggests long-term change.”

The word “This” in the passage refers to

• experiment
• corticosterone
• cortisol
• stress

Corticosterone

Corticosterone is described under the article and also says about the process of artificially of the hormone on the mice.

Darwin's theory is that 'selective breeding' occurs in nature as 'natural selection' is the engine behind evolution. Thus, the theory provides an excellent basis for understanding how organisms change over time. Nevertheless, it is just a theory and elusively difficult to prove. One of the major holes in Darwin's theory revolves around “irreducibly complex systems.” An irreducibly complex system is known as a system where many different parts must all operate together. As a result, in the absence of one, the system as a whole collapses. Consequently, as modern technology improves, science can identify these “irreducibly complex systems” even at microscopic levels. These complex systems, if so inter-reliant, would be resistant to Darwin's supposition of how evolution occurs. As Darwin himself admitted, “To suppose that the eye with all its inimitable contrivances for adjusting the focus for different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I free confess, absurd in the highest degree.

In paragraph, what was the author's purpose of including a quote that the belief that the complexity of the human eye could have been formed by natural selection seems highly unlikely?

• To provide evidence that irreducibly complex systems exist
• The proof that the natural selection contradicts the basis of Darwin
• The support that the natural selection contributes to the basis of Darwin
• The support the claim that natural selection is just a theory and difficult to prove

The support the claim that natural selection is just a theory and difficult to prove.

Darwin created the theory and acknowledges that some of the occurrences are difficult to believe and difficult to prove.

The assessment of past rises and falls in sea level requires study of submerged land surfaces off the coast and of elevated beaches on land. Raised beaches are remnants of former coastlines at higher levels relative to the present shoreline and visible, for instance, along the California coast north of San Francisco, the height of a raised beach above the present shoreline, however, does not generally give a straightforward indication of the height of a former sea level.

The word "remnants" in the passage is closest in meaning to -

• remains
• regions
• pints
• origins

Remains

We can guess the answer. We all kow the meaning of former and the meaning of "remnants" is related to this.

Read the following passage and paraphrase it by putting it into your own words.

In 1610, Galileo Galilei published a small book describing astronomical observations that he had made of the skies above Padua. His homemade telescopes had less magnifying and resolving power than most beginners’ telescopes sold today, yet with them he made astonishing discoveries: that the moon has mountains and other topographical features; that Jupiter is orbited by satellites, which he called planets; and that the Milky Way is made up of individual stars. From David Owen, “The Dark Side: Making War on Light Pollution,” The New Yorker (20 August 2007): 28.

You Need To Praphrase This As Per Your Own.

Examine the four # in the selection below and indicate at which block the following sentence could be inserted into the passage:

Seagrasses grow together in dense patches, or beds, with as many as 4,000 blades per square meter.:

Many areas of the shallow sea bottom are covered with a lush growth of aquatic flowering plants adapted to live submerged in seawater.

#These plants are collectively called seagrasses.

#Seagrass beds are strongly influenced by several physical factors.

#The most significant is water motion: currents and waves.

#Since seagrass systems exist in both sheltered and relatively open areas, they are subject to differing amounts of water motion.

Seagrass beds are strongly influenced by several physical factors.

It contains the specific imformation.