Small, flat structures called spatulae are found at the tips of the hairs on a spider’s leg. These spatulae temporarily bond with the atoms of whatever they touch. ______blank spiders are able to cling to and climb almost any surface.

In 1873, Spanish scientist Santiago Ramón y Cajal observed that brain fibers have distinct boundaries with clear end points, a finding that went against earlier assumptions about the brain. ______blank scientists had assumed that the brain was a continuous web of fused fibers, not a vast network of distinct, individual cells. 

Etched into Peru’s Nazca Desert are line drawings so large that they can only be fully seen from high above. Archaeologists have known of the lines since the 1920s, when a researcher spotted some from a nearby foothill, and they have been studying the markings ever since. ______blank archaeologists’ efforts are aided by drones that capture high-resolution aerial photographs of the lines.

Most of the planets that have been discovered outside our solar system orbit G-type stars, like our Sun. In 2014, ______blank researchers identified a planet orbiting KELT-9, a B-type star more than twice as massive and nearly twice as hot as the Sun. Called KELT-9b, it is one of the hottest planets ever discovered.

While researching a topic, a student has taken the following notes:

• Jordan Bennett is a Mi’Kmaq visual artist.
• The Mi’Kmaq are a First Nations people in North America.
• Bennett’s paintings pay homage to traditional Mi’Kmaq craftsmanship and have been displayed in over 75 exhibitions.
• His 2017 exhibition Wije’wi was held at the Grenfell Art Gallery.
• His 2018 exhibition Ketu’elmita’jik was held at the Art Gallery of Nova Scotia.

In 1968, US Congressman John Conyers introduced a bill to establish a national holiday in honor of Dr. Martin Luther King Jr. The bill didn’t make it to a vote, but Conyers was determined. He teamed up with Shirley Chisholm, the first Black woman to be elected to Congress, and they resubmitted the bill every session for the next fifteen years. ______blank in 1983, the bill passed.

Alexander Lawrence Posey (1873–1908) varied his focus and tone depending on the genre in which he was writing. In his poetry, he used heartfelt language to evoke the beauty and peacefulness of his natural surroundings; in his journalism, ______blank he employed humor and satire to comment on political issues affecting his Muskogee Creek community.

While researching a topic, a student has taken the following notes:

• Organisms release cellular material into their environment by shedding substances such as hair or skin.
• The DNA in these substances is known as environmental DNA, or eDNA.
• Researchers collect and analyze eDNA to detect the presence of species that are difficult to observe.
• Geneticist Sara Oyler-McCance’s research team analyzed eDNA in water samples from the Florida Everglades to detect invasive constrictor snake species in the area.
• The study determined a 91% probability of detecting Burmese python eDNA in a given location.

Jhumpa Lahiri’s story collection Interpreter of Maladies features multiple stories about romantic relationships. In “This Blessed House,” newlyweds argue over whether to replace items left by the previous owners of their new home. ______blank in “A Temporary Matter,” a husband and wife attempt to rekindle their relationship during a four-night blackout.

While researching a topic, a student has taken the following notes:

• In 2020, theater students at Radford and Virginia Tech chose an interactive, online format to present a play about woman suffrage activists.
• Their “Women and the Vote” website featured an interactive digital drawing of a Victorian-style house.
• Audiences were asked to focus on a room of their choice and select from that room an artifact related to the suffrage movement.
• One click took them to video clips, songs, artwork, and texts associated with the artifact.
• The play was popular with audiences because the format allowed them to control the experience.

While researching a topic, a student has taken the following notes:

• Muckrakers were journalists who sought to expose corruption in US institutions during the Progressive Era (1897–1920).
• Ida Tarbell was a muckraker who investigated the Standard Oil Company.
• She interviewed Standard Oil Company executives, oil industry workers, and public officials.
• She examined thousands of pages of the company’s internal communications, including letters and financial records.
• Her book The History of the Standard Oil Company (1904) exposed the company’s unfair business practices.

Tyrian purple was a highly prized dye among the Phoenicians (an ancient civilization located in present-day Lebanon). The Phoenicians were famous for using this natural dye to color their clothes a distinctive purple. ______blank the name “Phoenicia” itself, some historians claim, may have originally meant “land of purple.”

While researching a topic, a student has taken the following notes:

• The Philadelphia and Lancaster Turnpike was a road built between 1792 and 1794.
• It was the first private turnpike in the United States.
• It connected the cities of Philadelphia and Lancaster in the state of Pennsylvania.
• It was sixty-two miles long.

While researching a topic, a student has taken the following notes:

• Marine biologist Camille Jazmin Gaynus studies coral reefs.
• Coral reefs are vital underwater ecosystems that provide habitats to 25% of all marine species.
• Reefs can include up to 8,000 species of fish, such as toadfish, seahorses, and clown triggerfish.
• The Amazon Reef is a coral reef in Brazil.
• It is one of the largest known reefs in the world.

While researching a topic, a student has taken the following notes:

• Muslins are woven cotton fabrics with a variety of uses.
• Dhaka muslin is a handmade fabric produced in Dhaka, Bangladesh.
• It has an extremely fine weave and is primarily used to make luxury clothing.
• Sheeting muslin is a machine-made fabric produced in factories.
• It has a coarse weave and is primarily used to upholster furniture and create backdrops for theater sets.