Digital SAT Main Idea & Structure Practice Questions

1. In the 1880s, astronomer Mary Adela Blagg began studying the Moon’s surface using maps produced by earlier observers. She noticed that the same lunar feature was often given different names in different maps, while some names were used inconsistently for more than one feature. To reduce this confusion, Blagg compared existing lunar maps and catalogs, identified duplicate or conflicting names, and helped produce a standardized list of lunar nomenclature. Her work did not involve discovering new craters, but it made future lunar research easier by giving scientists a more reliable way to refer to the Moon’s surface.

Which choice best states the main idea of the text?

A) Although Mary Adela Blagg did not discover new lunar features, her work helped make the study of the Moon more systematic.

B) Mary Adela Blagg showed that most earlier lunar maps were too inaccurate to be useful to astronomers.

C) By comparing lunar maps, Mary Adela Blagg proved that different astronomers had discovered the same craters independently.

D) Mary Adela Blagg’s main contribution was creating a new map of the Moon that replaced earlier maps.

Question 1 of 5

2. During the early twentieth century, many historians described ancient trade routes mainly as channels through which luxury goods moved between distant regions. More recent researchers, however, have examined shipping records, household objects, and archaeological remains to show that these routes also carried ordinary items such as grain, tools, and textiles. This newer approach has broadened scholars’ understanding of trade by suggesting that long-distance exchange affected daily life for many people, not just wealthy merchants and rulers.

Which choice best states the main idea of the text?

A) Historians once believed that luxury goods were more valuable than grain, tools, and textiles in ancient markets.

B) Archaeologists have recently proven that wealthy merchants controlled all major ancient trade routes.

C) Newer research suggests that ancient trade routes influenced everyday life more broadly than earlier historians had recognized.

D) Because shipping records are often incomplete, historians can know little about the purpose of ancient trade routes.

Question 2 of 5

3. For many years, biologists assumed that brightly colored flowers evolved mainly to attract bees, which can detect a wide range of colors. Recently, however, researchers studying bird-pollinated plants have noted that many red flowers produce relatively little scent but abundant nectar. Because many birds rely more on vision than smell when locating food, these findings suggest that some floral traits may reflect adaptation to birds rather than to bees alone. The research has encouraged scientists to view flower color as the result of multiple pollinators’ influences.

Which choice best states the main idea of the text?

A) Bees are less important to plant evolution than biologists previously believed.

B) Red flowers evolved because birds are unable to smell floral scents.

C) Scientists have determined that birds prefer nectar to all other food sources.

D) Recent research suggests that flower traits once attributed mainly to bee pollination may also reflect adaptation to bird pollinators.

Question 3 of 5

4. When public libraries first began lending motion pictures in the mid-twentieth century, some critics argued that the collections should contain only documentaries and educational films. Librarians in many cities, however, found that patrons were far more likely to borrow feature films, which often introduced them to actors, directors, or historical periods they later explored through books and lectures. As a result, many libraries expanded their film collections, treating popular entertainment not as a distraction from learning but as a pathway to it.

Which choice best states the main idea of the text?

A) Libraries came to view popular films as a useful way to encourage broader learning and engagement.

B) Critics of library film collections believed documentaries were less informative than feature films.

C) Most library patrons borrowed feature films only after attending lectures on cinema history.

D) Libraries expanded their film collections because documentaries were too expensive to acquire.

Question 4 of 5

5. In the late nineteenth century, some city planners believed that urban parks were primarily decorative spaces meant to beautify crowded neighborhoods. Reformers soon began arguing, however, that parks could also improve public health by providing cleaner air and room for exercise. In response, several cities redesigned existing parks to include walking paths, playgrounds, and athletic fields. These changes reflected a broader shift in how public officials understood the purpose of urban green spaces.

Which choice best describes the overall structure of the text?

A) It describes the construction of several parks and then argues that most of them failed to achieve their intended purpose.

B) It explains why urban parks became less popular over time and then proposes ways cities might restore them.

C) It presents an early view of city parks, describes a competing newer view, and then explains changes that resulted from that newer view.

D) It compares park designs in different cities and concludes that decorative parks were more successful than recreational ones.

Question 5 of 5