可汗SAT语法48篇：Classifying the Stars
Questions 1-5 are based on the following passage.
Classifying the Stars
In astronomy, stellar classification is governed by the Morgan-Keenen system, which categorizes stars based on their composition and surface temperature. The origins of this system can be traced back to the work of Annie Jump Cannon, a late nineteenth-century and early twentieth-century ①astronomer. Spending over forty years classifying stars based on their unique spectra of transmitted light.
 Beginning early in her life, Cannon demonstrated an exceptional aptitude for the physical sciences.  Later, as a student at Wellesley College, Cannon earned a degree in physics and became an expert in spectroscopy: the process by which light is separated into its component wavelengths.  During this period, she also took up photography and traveled extensively in order to experiment with the newly invented black-box camera.  As a child, she developed an interest in astronomy and purportedly used her attic as a makeshift observatory. ②
Cannon‘s background in physics, astronomy, and photography provided her with a unique skillset that ③ will serve her well for the rest of her career. After working as a research assistant for a number of astronomers at Wellesley and Radcliffe Colleges, Cannon was hired by Professor Edward Charles Pickering, the director of the Harvard College Observatory. Under Pickering, she classified over 300,000 stars-more than any other human in history-using only a telescope, a spectrometer, and a camera. Using this knowledge, she developed her own classification system that relied on the surface temperature of the stars, which could be approximated using the spectrum of light transmitted from each star. It was said that Cannon could classify three stars a minute and, using a magnifying glass, could classify stars down to the 9th magnitude-sixteen times fainter than ④ humans. Today, Cannon‘s unique classification system is used by countless astronomy enthusiasts around the world.
⑤ Pickering was succeeded by Harlow Shapley.Shapley once said that Cannon's contribution to astronomy was “a structure that probably will never be duplicated in kind or extent by a single individual.” Indeed, Cannon‘s work has forever shaped our comprehension and perception of the vast and elaborate universe.
A) NO CHANGE
B) astronomer, she spent
C) astronomer spent
D) astronomer who spent
To make the paragraph most logical, sentence 4 should be placed
A) where it is now.
B) before sentence 1.
C) after sentence 1.
D) after sentence 2.
A) NO CHANGE
C) would serve
D) has served
A) NO CHANGE
B) the human eye.
C) that of the human eye.
D) what can be seen by the human eye.
Which choice most effectively combines the underlined sentences?
A) Harlow Shapley, who once said Cannon‘s contribution to astronomy was ―a structure that probably will never be duplicated in kind or extent by a single individual," was Pickering‘s successor.
B) Pickering was succeeded by Harlow Shapley, and Shapley once said that Cannon‘s contribution to astronomy was ―a structure that probably will never be duplicated in kind or extent by a single individual."
C) ―A structure that probably will never be duplicated in kind or extent by a single individual" was once said by Pickering‘s successor, Harlow Shapley, about Cannon‘s contribution to astronomy.
D) Harlow Shapley, the astronomer who succeeded Pickering, once referred to Cannon‘s contribution to astronomy as ―a structure that probably
will never be duplicated in kind or extent by a